[alsa-devel] [PATCH] ALSA: hda - PCH HDA controller not controlled by i915 power

[Takashi Iwai]

At Tue,  9 Jun 2015 14:05:18 +0800,
libin.yang at intel.com wrote:
> 
> From: Libin Yang <libin.yang at intel.com>
> 
> On some Intel platforms, the HDMI codec is connected to PCH HDA
> controller. In this case, AZX_DCAPS_I915_POWERWELL is set and
> the i915 power well failure should not block the hda controller
> initialization.
> 
> Signed-off-by: Libin Yang <libin.yang at intel.com>

Is this fix needed for 4.1, or it's only for 4.2?
I vaguely remember of a bug report.  If there is any relevant bug
report, please give the link, too.


Takashi

> ---
>  sound/hda/hdac_i915.c     |  6 +++---
>  sound/pci/hda/hda_intel.c | 11 +++++++++--
>  2 files changed, 12 insertions(+), 5 deletions(-)
> 
> diff --git a/sound/hda/hdac_i915.c b/sound/hda/hdac_i915.c
> index cb78c25..4f4036a 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);
> diff --git a/sound/pci/hda/hda_intel.c b/sound/pci/hda/hda_intel.c
> index 7933fb0..775e020 100644
> --- a/sound/pci/hda/hda_intel.c
> +++ b/sound/pci/hda/hda_intel.c
> @@ -1986,14 +1986,21 @@ static int azx_probe_continue(struct azx *chip)
>  			hda->need_i915_power = 1;
>  
>  		err = snd_hdac_i915_init(bus);
> +		/* if controller is located in powerwell,
> +		 * the initialization should be stopped.
> +		 * if only codec is located in powerwell,
> +		 * the hd audio is still ok for analog audio
> +		 */
>  		if (err < 0)
> -			goto i915_power_fail;
> +			if (hda->need_i915_power)
> +				goto i915_power_fail;
>  
>  		err = snd_hdac_display_power(bus, true);
>  		if (err < 0) {
>  			dev_err(chip->card->dev,
>  				"Cannot turn on display power on i915\n");
> -			goto i915_power_fail;
> +			if (hda->need_i915_power)
> +				goto i915_power_fail;
>  		}
>  	}
>  
> -- 
> 1.9.1
>