[alsa-devel] [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de --- This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0) - goto out_free; + goto skip_i915; err = hda_display_power(hda, true); if (err < 0) { dev_err(chip->card->dev, @@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
+ skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
Add the missing NULL checks so that snd_hdac_i915*() can be called even after the binding with i915 failed.
Signed-off-by: Takashi Iwai tiwai@suse.de --- This is only for 4.2 (for-next branch).
sound/hda/hdac_i915.c | 11 +++++++---- 1 file changed, 7 insertions(+), 4 deletions(-)
diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c index cb78c25585ac..442500e06b7c 100644 --- a/sound/hda/hdac_i915.c +++ b/sound/hda/hdac_i915.c @@ -27,7 +27,7 @@ int snd_hdac_set_codec_wakeup(struct hdac_bus *bus, bool enable) { struct i915_audio_component *acomp = bus->audio_component;
- if (!acomp->ops) + if (!acomp || !acomp->ops) return -ENODEV;
if (!acomp->ops->codec_wake_override) { @@ -49,7 +49,7 @@ int snd_hdac_display_power(struct hdac_bus *bus, bool enable) { struct i915_audio_component *acomp = bus->audio_component;
- if (!acomp->ops) + if (!acomp || !acomp->ops) return -ENODEV;
dev_dbg(bus->dev, "display power %s\n", @@ -72,7 +72,7 @@ int snd_hdac_get_display_clk(struct hdac_bus *bus) { struct i915_audio_component *acomp = bus->audio_component;
- if (!acomp->ops) + if (!acomp || !acomp->ops) return -ENODEV;
return acomp->ops->get_cdclk_freq(acomp->dev); @@ -179,8 +179,11 @@ int snd_hdac_i915_exit(struct hdac_bus *bus) struct device *dev = bus->dev; struct i915_audio_component *acomp = bus->audio_component;
+ if (!acomp) + return 0; + WARN_ON(bus->i915_power_refcount); - if (bus->i915_power_refcount > 0 && acomp && acomp->ops) + if (bus->i915_power_refcount > 0 && acomp->ops) acomp->ops->put_power(acomp->dev);
component_master_del(dev, &hdac_component_master_ops);
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain: - Its PCI configuration space is out of i915 power well, but in an always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
- Its audio functions are in the i915 power well. If hda_i915_init() fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
Thanks Mengdong
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an always-on
power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init() fails and
I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
thanks,
Takashi
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init()
fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
Thanks Mengdong
At Fri, 12 Jun 2015 05:50:43 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init()
fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
thanks,
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: hda - Abort the probe without i915 binding for HSW/BDW
The previous patch tried to continue the probe if i915 binding fails. For for simplicity reason, we haven't implemented abort even for controller chips that are dedicated for HDMI/DP on HSW and BDW. However, Mengdong suggested that this can be dangerous; BIOS may disable gfx power well although the PCI entry for HD-audio is left, and this may result in the unexpected behavior, kernel errors, etc.
For avoiding this situation, abort the probe at i915 binding failure only for HSW/BDW chips selectively. For other chips, it still continues.
Fixes: bf06848bdbe5 ('ALSA: hda - Continue probing even if i915 binding fails') Reported-by: Mengdong Lin mengdong.lin@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de --- sound/pci/hda/hda_intel.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 8a0af6770e1d..a244ba706317 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -340,6 +340,11 @@ enum { #define use_vga_switcheroo(chip) 0 #endif
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \ + ((pci)->device == 0x0c0c) || \ + ((pci)->device == 0x0d0c) || \ + ((pci)->device == 0x160c)) + static char *driver_short_names[] = { [AZX_DRIVER_ICH] = "HDA Intel", [AZX_DRIVER_PCH] = "HDA Intel PCH", @@ -1854,8 +1859,17 @@ static int azx_probe_continue(struct azx *chip) if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); - if (err < 0) - goto skip_i915; + if (err < 0) { + /* if the controller is bound only with HDMI/DP + * (for HSW and BDW), we need to abort the probe; + * for other chips, still continue probing as other + * codecs can be on the same link. + */ + if (CONTROLLER_IN_GPU(pci)) + goto out_free; + else + goto skip_i915; + } err = hda_display_power(hda, true); if (err < 0) { dev_err(chip->card->dev,
On 2015-06-12 08:06, Takashi Iwai wrote:
At Fri, 12 Jun 2015 05:50:43 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init()
fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
thanks,
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: hda - Abort the probe without i915 binding for HSW/BDW
The previous patch tried to continue the probe if i915 binding fails. For for simplicity reason, we haven't implemented abort even for controller chips that are dedicated for HDMI/DP on HSW and BDW. However, Mengdong suggested that this can be dangerous; BIOS may disable gfx power well although the PCI entry for HD-audio is left, and this may result in the unexpected behavior, kernel errors, etc.
For avoiding this situation, abort the probe at i915 binding failure only for HSW/BDW chips selectively. For other chips, it still continues.
Fixes: bf06848bdbe5 ('ALSA: hda - Continue probing even if i915 binding fails') Reported-by: Mengdong Lin mengdong.lin@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
sound/pci/hda/hda_intel.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 8a0af6770e1d..a244ba706317 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -340,6 +340,11 @@ enum { #define use_vga_switcheroo(chip) 0 #endif
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
((pci)->device == 0x0c0c) || \((pci)->device == 0x0d0c) || \((pci)->device == 0x160c))- static char *driver_short_names[] = { [AZX_DRIVER_ICH] = "HDA Intel", [AZX_DRIVER_PCH] = "HDA Intel PCH",
@@ -1854,8 +1859,17 @@ static int azx_probe_continue(struct azx *chip) if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda);
if (err < 0)goto skip_i915;
if (err < 0) {/* if the controller is bound only with HDMI/DP* (for HSW and BDW), we need to abort the probe;* for other chips, still continue probing as other* codecs can be on the same link.*/if (CONTROLLER_IN_GPU(pci))goto out_free;elsegoto skip_i915;}
At Fri, 12 Jun 2015 08:17:12 +0200, David Henningsson wrote:
On 2015-06-12 08:06, Takashi Iwai wrote:
At Fri, 12 Jun 2015 05:50:43 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init()
fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
I don't see much usefulness there but rather simplicity.
The binding with i915 won't happen at the later stage, thus the device is just a placeholder. Any other goodies by keeping the dead device?
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
One point that hasn't been mentioned is the behavior change from the previous kernels. The previous kernels abort probing, and it was OK since we supposed only HSW/BDW before 4.1. Now, with continuing the probe, user sees the new device that hasn't been there, and yet the device is dead and merely a placeholder.
thanks,
Takashi
thanks,
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: hda - Abort the probe without i915 binding for HSW/BDW
The previous patch tried to continue the probe if i915 binding fails. For for simplicity reason, we haven't implemented abort even for controller chips that are dedicated for HDMI/DP on HSW and BDW. However, Mengdong suggested that this can be dangerous; BIOS may disable gfx power well although the PCI entry for HD-audio is left, and this may result in the unexpected behavior, kernel errors, etc.
For avoiding this situation, abort the probe at i915 binding failure only for HSW/BDW chips selectively. For other chips, it still continues.
Fixes: bf06848bdbe5 ('ALSA: hda - Continue probing even if i915 binding fails') Reported-by: Mengdong Lin mengdong.lin@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
sound/pci/hda/hda_intel.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 8a0af6770e1d..a244ba706317 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -340,6 +340,11 @@ enum { #define use_vga_switcheroo(chip) 0 #endif
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
((pci)->device == 0x0c0c) || \((pci)->device == 0x0d0c) || \((pci)->device == 0x160c))- static char *driver_short_names[] = { [AZX_DRIVER_ICH] = "HDA Intel", [AZX_DRIVER_PCH] = "HDA Intel PCH",
@@ -1854,8 +1859,17 @@ static int azx_probe_continue(struct azx *chip) if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda);
if (err < 0)goto skip_i915;
if (err < 0) {/* if the controller is bound only with HDMI/DP* (for HSW and BDW), we need to abort the probe;* for other chips, still continue probing as other* codecs can be on the same link.*/if (CONTROLLER_IN_GPU(pci))goto out_free;elsegoto skip_i915;}
At Fri, 12 Jun 2015 08:37:38 +0200, Takashi Iwai wrote:
At Fri, 12 Jun 2015 08:17:12 +0200, David Henningsson wrote:
On 2015-06-12 08:06, Takashi Iwai wrote:
At Fri, 12 Jun 2015 05:50:43 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
> -----Original Message----- > From: Takashi Iwai [mailto:tiwai@suse.de] > Sent: Wednesday, June 10, 2015 6:26 PM > > Currently snd-hda-intel driver aborts the probing of Intel HD-audio > controller with i915 power well management when binding with i915 > driver via > hda_i915_init() fails. This is no big problem for Haswell and > Broadwell where the HD-audio controllers are dedicated to HDMI/DP, > thus i915 link is mandatory. However, Skylake, Baytrail and > Braswell have only one controller and both HDMI/DP and analog codecs > share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
> For fixing this, this patch simply allows continuing the probing > even if > hda_i915_init() call fails. This may leave stale sound components > for HDMI/DP devices that are unbound with graphics. We could abort > the probing selectively, but from the code simplicity POV, it's > better to continue in all cases. > > Reported-by: Libin Yang libin.yang@intel.com > Signed-off-by: Takashi Iwai tiwai@suse.de > --- > This is for 4.1. Appying to 4.2 may result in trivial conflicts. > > sound/pci/hda/hda_intel.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c > index fea198c58196..8a0af6770e1d 100644 > --- a/sound/pci/hda/hda_intel.c > +++ b/sound/pci/hda/hda_intel.c > @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx > *chip) #ifdef CONFIG_SND_HDA_I915 > err = hda_i915_init(hda); > if (err < 0) > - goto out_free; > + goto skip_i915; > err = hda_display_power(hda, true); > if (err < 0) { > dev_err(chip->card->dev, > @@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx > *chip) #endif > } > > + skip_i915: > err = azx_first_init(chip); > if (err < 0) > goto out_free; > -- > 2.4.3 Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If hda_i915_init()
fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
I don't see much usefulness there but rather simplicity.
The binding with i915 won't happen at the later stage, thus the device is just a placeholder. Any other goodies by keeping the dead device?
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
One point that hasn't been mentioned is the behavior change from the previous kernels. The previous kernels abort probing, and it was OK since we supposed only HSW/BDW before 4.1. Now, with continuing the probe, user sees the new device that hasn't been there, and yet the device is dead and merely a placeholder.
Is this convincing enough for you? Or would you still like to make the broken HDMI/DP device enabled for HSW/BDW?
Takashi
On 2015-06-12 16:14, Takashi Iwai wrote:
At Fri, 12 Jun 2015 08:37:38 +0200, Takashi Iwai wrote:
At Fri, 12 Jun 2015 08:17:12 +0200, David Henningsson wrote:
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
I don't see much usefulness there but rather simplicity.
The binding with i915 won't happen at the later stage, thus the device is just a placeholder. Any other goodies by keeping the dead device?
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
One point that hasn't been mentioned is the behavior change from the previous kernels. The previous kernels abort probing, and it was OK since we supposed only HSW/BDW before 4.1. Now, with continuing the probe, user sees the new device that hasn't been there, and yet the device is dead and merely a placeholder.
Is this convincing enough for you? Or would you still like to make the broken HDMI/DP device enabled for HSW/BDW?
I guess the question is whether HDMI/DP can actually work without the i915 driver, e g when running with nomodeset. If there is absolutely no possibility whatsoever (e g maybe BIOS could set up the device so that it works?), then it does not matter much, I suppose.
At Fri, 12 Jun 2015 16:33:32 +0200, David Henningsson wrote:
On 2015-06-12 16:14, Takashi Iwai wrote:
At Fri, 12 Jun 2015 08:37:38 +0200, Takashi Iwai wrote:
At Fri, 12 Jun 2015 08:17:12 +0200, David Henningsson wrote:
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
I don't see much usefulness there but rather simplicity.
The binding with i915 won't happen at the later stage, thus the device is just a placeholder. Any other goodies by keeping the dead device?
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
One point that hasn't been mentioned is the behavior change from the previous kernels. The previous kernels abort probing, and it was OK since we supposed only HSW/BDW before 4.1. Now, with continuing the probe, user sees the new device that hasn't been there, and yet the device is dead and merely a placeholder.
Is this convincing enough for you? Or would you still like to make the broken HDMI/DP device enabled for HSW/BDW?
I guess the question is whether HDMI/DP can actually work without the i915 driver, e g when running with nomodeset. If there is absolutely no possibility whatsoever (e g maybe BIOS could set up the device so that it works?), then it does not matter much, I suppose.
It can't work because we don't get proper ELD thus cannot setup HDMI/DP CA bits.
Takashi
-----Original Message----- From: David Henningsson [mailto:david.henningsson@canonical.com] Sent: Friday, June 12, 2015 2:17 PM To: Takashi Iwai; Lin, Mengdong Cc: alsa-devel@alsa-project.org; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
On 2015-06-12 08:06, Takashi Iwai wrote:
At Fri, 12 Jun 2015 05:50:43 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Friday, June 12, 2015 1:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org; David Henningsson; Yang, Libin Subject: Re: [PATCH 1/2] ALSA: hda - Continue probing even if i915 binding fails
At Fri, 12 Jun 2015 02:08:50 +0000, Lin, Mengdong wrote:
-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Wednesday, June 10, 2015 6:26 PM
Currently snd-hda-intel driver aborts the probing of Intel HD-audio controller with i915 power well management when binding with i915 driver via hda_i915_init() fails. This is no big problem for Haswell and Broadwell where the HD-audio controllers are dedicated to HDMI/DP, thus i915 link is mandatory. However, Skylake, Baytrail and Braswell have only one controller and both HDMI/DP and analog codecs share the same bus. Thus, even if HDMI/DP isn't usable, we should keep
the controller working for other codecs.
For fixing this, this patch simply allows continuing the probing even if hda_i915_init() call fails. This may leave stale sound components for HDMI/DP devices that are unbound with graphics. We could abort the probing selectively, but from the code simplicity POV, it's better to continue in all cases.
Reported-by: Libin Yang libin.yang@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
This is for 4.1. Appying to 4.2 may result in trivial conflicts.
sound/pci/hda/hda_intel.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index fea198c58196..8a0af6770e1d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -1855,7 +1855,7 @@ static int azx_probe_continue(struct azx *chip) #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0)
goto out_free;
goto skip_i915;@@ -1865,6 +1865,7 @@ static int azx_probe_continue(struct azx *chip) #endif }
- skip_i915: err = azx_first_init(chip); if (err < 0) goto out_free;
-- 2.4.3
Thanks for your patch. But maybe we should not skip i915 for the dedicated display HD-A controller on Haswell/Broadwell.
For HSW/BDW, their HD-A controller for display audio (PCI dev#3) is *partly* in GPU power domain:
- Its PCI configuration space is out of i915 power well, but in an
always-on power well. So even if the BIOS disables the Intel GPU (PCI dev#2), the HD-A controller is still present, and we can still access all standard registers in PCI config space.
Right, and changing this doesn't break things.
- Its audio functions are in the i915 power well. If
hda_i915_init() fails and I915 power well is unavailable, read/write to the audio register of the Controller will fail and we'll get kernel error messages. So I feel it's better to abort if hda_i915_init() fails for this HD-A
controller.
By skipping, the access to i915 power well won't happen later, since the component ops isn't set.
I tested Haswell machines with nomodeset to simulate the situation, and there was no any kernel errors except for the first one indicating the failure of i915 binding.
I haven't tested Broadwell, though.
Hi Takashi,
I think there is no error because the i915 power well is ON by default on Haswell and BIOS does not touch this. However, it's possible that the BIOS may disable this power well and depends on i915 driver to turn it on when need, or just disable the power well when
disabling the Intel GPU.
I remember previously we met audio register I/O error when HSW introduced this power well and i915 disabled it without sync with audio
driver.
Since we cannot expect the exact BIOS behavior, I feel it's safer not to use this HD-A controller without i915 on HSW and BDW.
If BIOS disables the power well, then we would get the "audio register I/O error" in the boot phase, there will be no codecs detected, and thus no broken sound card showing up.
The only issue is if the i915 driver disables the power well, but the case that the i915 should be functioning enough to turn off the power well at some point, and at the same time so broken that we can't bind to it, seems extremely unlikely to me.
Either the i915 driver works, or it does not. In both cases, continuing probing is the more useful option.
The BIOS behavior is not decided. If i915 driver is broken, the power well status is not decided. Without this power well, the audio functions in this HD-A controller is dead, all access to HW will fail including the operation to reset link. So I feel it's better we need not continue the probing.
Thanks Mengdong
Fair enough. Then I'm going to queue the patch below in addition to for-linus branch.
We'll have to agree to disagree on that, then.
thanks,
Takashi
-- 8< -- From: Takashi Iwai tiwai@suse.de Subject: [PATCH] ALSA: hda - Abort the probe without i915 binding for HSW/BDW
The previous patch tried to continue the probe if i915 binding fails. For for simplicity reason, we haven't implemented abort even for controller chips that are dedicated for HDMI/DP on HSW and BDW. However, Mengdong suggested that this can be dangerous; BIOS may disable gfx power well although the PCI entry for HD-audio is left, and this may result in the unexpected behavior, kernel errors, etc.
For avoiding this situation, abort the probe at i915 binding failure only for HSW/BDW chips selectively. For other chips, it still continues.
Fixes: bf06848bdbe5 ('ALSA: hda - Continue probing even if i915 binding fails') Reported-by: Mengdong Lin mengdong.lin@intel.com Signed-off-by: Takashi Iwai tiwai@suse.de
sound/pci/hda/hda_intel.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index 8a0af6770e1d..a244ba706317 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -340,6 +340,11 @@ enum { #define use_vga_switcheroo(chip) 0 #endif
+#define CONTROLLER_IN_GPU(pci) (((pci)->device == 0x0a0c) || \
((pci)->device == 0x0c0c) || \((pci)->device == 0x0d0c) || \((pci)->device == 0x160c))- static char *driver_short_names[] = { [AZX_DRIVER_ICH] = "HDA Intel", [AZX_DRIVER_PCH] = "HDA Intel PCH", @@ -1854,8 +1859,17 @@
static
int azx_probe_continue(struct azx *chip) if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda);
if (err < 0)goto skip_i915;
if (err < 0) {/* if the controller is bound only with HDMI/DP* (for HSW and BDW), we need to abort the probe;* for other chips, still continue probing as other* codecs can be on the same link.*/if (CONTROLLER_IN_GPU(pci))goto out_free;elsegoto skip_i915;}
participants (3)
-
David Henningsson -
Lin, Mengdong -
Takashi Iwai