[Intel-gfx] [PATCH] drm/i915: save state of AUD_FREQ_CNTRL on all gen9+ platforms

[Matt Roper]

On Tue, Dec 31, 2019 at 04:47:18PM +0200, Kai Vehmanen wrote:
> On old platforms the default values of AUD_FREQ_CNTRL are
> typically used (as set by BIOS), so this has not been an issue,
> but future platforms will definitely need this. Extend the state
> save logic to cover all gen9+ platforms.
> 
> Bspec: 49281
> Cc: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: Kai Vehmanen <kai.vehmanen at linux.intel.com>

Looks good to me.

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

Given that the lack of this save/restore was causing noticeable problems
on ICL/TGL, do you know whether the same problems were also seen on
EHL/JSL?  If so, we may want Cc: stable and Fixes: tags so that it gets
backported?


Matt

> ---
>  drivers/gpu/drm/i915/display/intel_audio.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
> index 27710098d056..e6517c5d83ae 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.c
> +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> @@ -849,7 +849,7 @@ static unsigned long i915_audio_component_get_power(struct device *kdev)
>  	ret = intel_display_power_get(dev_priv, POWER_DOMAIN_AUDIO);
>  
>  	if (dev_priv->audio_power_refcount++ == 0) {
> -		if (IS_TIGERLAKE(dev_priv) || IS_ICELAKE(dev_priv)) {
> +		if (INTEL_GEN(dev_priv) >= 9) {
>  			I915_WRITE(AUD_FREQ_CNTRL, dev_priv->audio_freq_cntrl);
>  			DRM_DEBUG_KMS("restored AUD_FREQ_CNTRL to 0x%x\n",
>  				      dev_priv->audio_freq_cntrl);
> @@ -1124,7 +1124,7 @@ static void i915_audio_component_init(struct drm_i915_private *dev_priv)
>  		return;
>  	}
>  
> -	if (IS_TIGERLAKE(dev_priv) || IS_ICELAKE(dev_priv)) {
> +	if (INTEL_GEN(dev_priv) >= 9) {
>  		dev_priv->audio_freq_cntrl = I915_READ(AUD_FREQ_CNTRL);
>  		DRM_DEBUG_KMS("init value of AUD_FREQ_CNTRL of 0x%x\n",
>  			      dev_priv->audio_freq_cntrl);
> -- 
> 2.17.1
> 

-- 
Matt Roper
Graphics Software Engineer
VTT-OSGC Platform Enablement
Intel Corporation
(916) 356-2795