-----Original Message----- From: Takashi Iwai [mailto:tiwai@suse.de] Sent: Monday, April 20, 2015 4:09 PM To: Lin, Mengdong Cc: alsa-devel@alsa-project.org Subject: Re: [PATCH] ALSA: hda - only sync BCLK to the display clock for Haswell & Broadwell
At Mon, 20 Apr 2015 16:04:05 +0800, mengdong.lin@intel.com wrote:
From: Mengdong Lin mengdong.lin@intel.com
Only Intel Haswell and Broadwell have a separate HD-A controller (PCI device 3) for display audio, which needs to get 24MHz HD-A link BCLK from the variable display core clock through vendor specific registers EM4 & EM5. Other platforms (Baytrail, Braswell and Skylake) don't have this
feature.
So a new driver quirk AZX_DCAPS_I915_SYNC_CLK is defined for the HSW/BDW display HD-A controller, to sync clock after the shared display
power is restored.
Signed-off-by: Mengdong Lin mengdong.lin@intel.com
diff --git a/sound/pci/hda/hda_controller.h b/sound/pci/hda/hda_controller.h index be1b7de..1729004 100644 --- a/sound/pci/hda/hda_controller.h +++ b/sound/pci/hda/hda_controller.h @@ -175,6 +175,7 @@ enum { SDI0, SDI1, SDI2, SDI3, SDO0, SDO1, SDO2,
SDO3 };
#define AZX_DCAPS_CORBRP_SELF_CLEAR (1 << 28) /* CORBRP clears
itself after reset */
#define AZX_DCAPS_NO_MSI64 (1 << 29) /* Stick to 32-bit MSIs */ #define AZX_DCAPS_SEPARATE_STREAM_TAG (1 << 30) /* capture and
playback use separate stream tag */
+#define AZX_DCAPS_I915_SYNC_CLK (1 << 31) /* Need to sync BCLK with
display clock */
enum { AZX_SNOOP_TYPE_NONE, diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index e1c2105..951263d 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -289,13 +289,13 @@ enum { #define AZX_DCAPS_INTEL_HASWELL \ (/*AZX_DCAPS_ALIGN_BUFSIZE |*/ AZX_DCAPS_COUNT_LPIB_DELAY |\ AZX_DCAPS_PM_RUNTIME | AZX_DCAPS_I915_POWERWELL |\
AZX_DCAPS_SNOOP_TYPE(SCH))
AZX_DCAPS_I915_SYNC_CLK | AZX_DCAPS_SNOOP_TYPE(SCH))/* Broadwell HDMI can't use position buffer reliably, force to use LPIB */ #define AZX_DCAPS_INTEL_BROADWELL \ (/*AZX_DCAPS_ALIGN_BUFSIZE |*/ AZX_DCAPS_POSFIX_LPIB |\ AZX_DCAPS_PM_RUNTIME | AZX_DCAPS_I915_POWERWELL |\
AZX_DCAPS_SNOOP_TYPE(SCH))
AZX_DCAPS_I915_SYNC_CLK | AZX_DCAPS_SNOOP_TYPE(SCH))#define AZX_DCAPS_INTEL_BRASWELL \ (AZX_DCAPS_INTEL_PCH | AZX_DCAPS_I915_POWERWELL) @@ -815,7
+815,8 @@
static int azx_resume(struct device *dev)
if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { hda_display_power(hda, true);
haswell_set_bclk(hda);
if (chip->driver_caps & AZX_DCAPS_I915_SYNC_CLK)haswell_set_bclk(hda);The dcaps bits are previous now, and it's pretty specific to i915, so I think it's better to move the check into hda_i915.c, i.e. add a PCI ID check in haswell_set_bclk(). Fixing the callee would results in even smaller changes than fixing each caller.
Okay, I'll revise the patch.
Thanks Mengdong