From: Mengdong Lin mengdong.lin@intel.com

A flag "link_power_control" is added to indicate whether a codec needs to control the link power. And a new bus ops link_power() is defined for the codec to request to enable/disable the link power.

Signed-off-by: Mengdong Lin mengdong.lin@intel.com

diff --git a/include/sound/hdaudio.h b/include/sound/hdaudio.h index 6a2e030..b97c59e 100644 --- a/include/sound/hdaudio.h +++ b/include/sound/hdaudio.h @@ -74,6 +74,7 @@ struct hdac_device {

/* misc flags */ atomic_t in_pm; /* suspend/resume being performed */ + bool link_power_control:1;

/* sysfs */ struct hdac_widget_tree *widgets; @@ -184,6 +185,8 @@ struct hdac_bus_ops { /* get a response from the last command */ int (*get_response)(struct hdac_bus *bus, unsigned int addr, unsigned int *res); + /* control the link power */ + int (*link_power)(struct hdac_bus *bus, bool enable); };

/* @@ -311,6 +314,7 @@ static inline void snd_hdac_codec_link_down(struct hdac_device *codec) int snd_hdac_bus_send_cmd(struct hdac_bus *bus, unsigned int val); int snd_hdac_bus_get_response(struct hdac_bus *bus, unsigned int addr, unsigned int *res); +int snd_hdac_link_power(struct hdac_device *codec, bool enable);

bool snd_hdac_bus_init_chip(struct hdac_bus *bus, bool full_reset); void snd_hdac_bus_stop_chip(struct hdac_bus *bus); diff --git a/sound/hda/hdac_device.c b/sound/hda/hdac_device.c index 55c7d08..cdee710 100644 --- a/sound/hda/hdac_device.c +++ b/sound/hda/hdac_device.c @@ -552,6 +552,21 @@ void snd_hdac_power_down_pm(struct hdac_device *codec) EXPORT_SYMBOL_GPL(snd_hdac_power_down_pm); #endif

+/* + * Enable/disable the link power for a codec. + */ +int snd_hdac_link_power(struct hdac_device *codec, bool enable) +{ + if (!codec->link_power_control) + return 0; + + if (codec->bus->ops->link_power) + return codec->bus->ops->link_power(codec->bus, enable); + else + return -EINVAL; +} +EXPORT_SYMBOL_GPL(snd_hdac_link_power); + /* codec vendor labels */ struct hda_vendor_id { unsigned int id; diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c index 2d8883f..a85242f 100644 --- a/sound/pci/hda/hda_codec.c +++ b/sound/pci/hda/hda_codec.c @@ -857,6 +857,7 @@ void snd_hda_codec_register(struct hda_codec *codec) return; if (device_is_registered(hda_codec_dev(codec))) { snd_hda_register_beep_device(codec); + snd_hdac_link_power(&codec->core, true); pm_runtime_enable(hda_codec_dev(codec)); /* it was powered up in snd_hda_codec_new(), now all done */ snd_hda_power_down(codec); @@ -883,6 +884,7 @@ static int snd_hda_codec_dev_free(struct snd_device *device) struct hda_codec *codec = device->device_data;

codec->in_freeing = 1; + snd_hdac_link_power(&codec->core, false); snd_hdac_device_unregister(&codec->core); put_device(hda_codec_dev(codec)); return 0; @@ -3102,6 +3104,7 @@ static int hda_codec_runtime_suspend(struct device *dev) if (codec_has_clkstop(codec) && codec_has_epss(codec) && (state & AC_PWRST_CLK_STOP_OK)) snd_hdac_codec_link_down(&codec->core); + snd_hdac_link_power(&codec->core, false); return 0; }

@@ -3109,6 +3112,7 @@ static int hda_codec_runtime_resume(struct device *dev) { struct hda_codec *codec = dev_to_hda_codec(dev);

+ snd_hdac_link_power(&codec->core, true); snd_hdac_codec_link_up(&codec->core); hda_call_codec_resume(codec); pm_runtime_mark_last_busy(dev);

From: Mengdong Lin mengdong.lin@intel.com

This patch can improve power saving for Intel platforms on which only the display audio codec is in the shared i915 power well:

- Add a flag "need_i915_power" to indicate whether the controller needs the i915 power well.

- The driver will always request the i915 power when probing the controller and codecs if AZX_DCAPS_I915_POWERWELL is set (either the controller or a codec needs this power).

- If the controller needs the i915 power, the power will be held after probe until the controller is runtime suspended or S3. If the controller doesn't need the power, the power will be released the after probe, and a codec that needs the power can request/release the power via bus link_power ops.

Background: - For Haswell/Broadwell, which has a separate HD-A controller for display audio, both the controller and the display codec are in the i915 power well.

- For Baytrail/Braswell, the display and analog audio share the same HDA controller and link, and only the display codec is in the i915 power well.

- For Skylake, the display and analog audio share the same HDA controller but use separate links. Only the display codec is in the i915 power well. And in legacy mode we take the two links as one. So it can follow Baytrail/Braswell.

Signed-off-by: Mengdong Lin mengdong.lin@intel.com

diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c index d70b405..98e721b 100644 --- a/sound/pci/hda/hda_intel.c +++ b/sound/pci/hda/hda_intel.c @@ -817,7 +817,8 @@ static int azx_suspend(struct device *dev)

if (chip->msi) pci_disable_msi(chip->pci); - if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL + && hda->need_i915_power) hda_display_power(hda, false); return 0; } @@ -837,7 +838,8 @@ static int azx_resume(struct device *dev) if (chip->disabled || hda->init_failed) return 0;

- if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL + && hda->need_i915_power) { hda_display_power(hda, true); haswell_set_bclk(hda); } @@ -880,7 +882,8 @@ static int azx_runtime_suspend(struct device *dev) azx_stop_chip(chip); azx_enter_link_reset(chip); azx_clear_irq_pending(chip); - if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL + && hda->need_i915_power) hda_display_power(hda, false);

return 0; @@ -905,7 +908,8 @@ static int azx_runtime_resume(struct device *dev) if (!azx_has_pm_runtime(chip)) return 0;

- if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL + && hda->need_i915_power) { hda_display_power(hda, true); haswell_set_bclk(hda); } @@ -1126,7 +1130,8 @@ static int azx_free(struct azx *chip) release_firmware(chip->fw); #endif if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { - hda_display_power(hda, false); + if (hda->need_i915_power) + hda_display_power(hda, false); hda_i915_exit(hda); } kfree(hda); @@ -1891,17 +1896,26 @@ static int azx_probe_continue(struct azx *chip) int err;

hda->probe_continued = 1; - /* Request power well for Haswell HDA controller and codec */ + + /* Request display power well for the HDA controller or codec. For + * Haswell/Broadwell, both the display HDA controller and codec need + * this power. For other platforms, like Baytrail/Braswell, only the + * display codec needs the power and it can be released after probe. + */ if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL) { + /* Assume the controller needs the power by default */ + hda->need_i915_power = 1; + #ifdef CONFIG_SND_HDA_I915 err = hda_i915_init(hda); if (err < 0) - goto out_free; + goto i915_power_fail; + err = hda_display_power(hda, true); if (err < 0) { dev_err(chip->card->dev, "Cannot turn on display power on i915\n"); - goto out_free; + goto i915_power_fail; } #endif } @@ -1948,6 +1962,11 @@ static int azx_probe_continue(struct azx *chip) pm_runtime_put_noidle(&pci->dev);

out_free: + if (chip->driver_caps & AZX_DCAPS_I915_POWERWELL + && !hda->need_i915_power) + hda_display_power(hda, false); + +i915_power_fail: if (err < 0) hda->init_failed = 1; complete_all(&hda->probe_wait); diff --git a/sound/pci/hda/hda_intel.h b/sound/pci/hda/hda_intel.h index dc1d3ff..505f987 100644 --- a/sound/pci/hda/hda_intel.h +++ b/sound/pci/hda/hda_intel.h @@ -45,6 +45,7 @@ struct hda_intel { struct dev_pm_domain hdmi_pm_domain;

/* i915 component interface */ + bool need_i915_power:1; /* the hda controller needs i915 power */ struct i915_audio_component audio_component; int i915_power_refcount; };