Re: [Intel-gfx] [PATCH 13/22] drm/i915/audio: Split "ELD valid" vs. audio PD on hsw+

[Jani Nikula <jani.nikula@linux.intel.com>]

On Tue, 11 Oct 2022, Ville Syrjala <ville.syrjala@linux.intel.com> wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>
> On the older platforms the audio presence detect bit is in
> the port register, so it gets written outside audio codec hooks
> and is this separate from the ELD valid toggling. Split the
> operations into two steps on hsw+ to be more consistent with
> both the other platforms and the spec. Also according to the
> spec we might need some vblank waits between the two which
> definitely needs them done separately.
>
> Cc: Chaitanya Kumar Borah <chaitanya.kumar.borah@intel.com>
> Cc: Kai Vehmanen <kai.vehmanen@linux.intel.com>
> Cc: Takashi Iwai <tiwai@suse.de>
> Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

Reviewed-by: Jani Nikula <jani.nikula@intel.com>

> ---
>  drivers/gpu/drm/i915/display/intel_audio.c | 16 +++++++++++-----
>  1 file changed, 11 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.c b/drivers/gpu/drm/i915/display/intel_audio.c
> index 1b928d283b8d..0a1ba10fc20d 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.c
> +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> @@ -479,9 +479,12 @@ static void hsw_audio_codec_disable(struct intel_encoder *encoder,
>  		     intel_crtc_has_dp_encoder(old_crtc_state) ?
>  		     AUD_CONFIG_N_VALUE_INDEX : 0);
>  
> -	/* Disable audio presence detect, invalidate ELD */
> +	/* Invalidate ELD */
> +	intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
> +		     AUDIO_ELD_VALID(cpu_transcoder), 0);
> +
> +	/* Disable audio presence detect */
>  	intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
> -		     AUDIO_ELD_VALID(cpu_transcoder) |
>  		     AUDIO_OUTPUT_ENABLE(cpu_transcoder), 0);
>  
>  	mutex_unlock(&i915->display.audio.mutex);
> @@ -612,10 +615,13 @@ static void hsw_audio_codec_enable(struct intel_encoder *encoder,
>  	if (intel_crtc_has_type(crtc_state, INTEL_OUTPUT_DP))
>  		enable_audio_dsc_wa(encoder, crtc_state);
>  
> -	/* Enable audio presence detect, invalidate ELD */
> +	/* Enable audio presence detect */
>  	intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
> -		     AUDIO_ELD_VALID(cpu_transcoder),
> -		     AUDIO_OUTPUT_ENABLE(cpu_transcoder));
> +		     0, AUDIO_OUTPUT_ENABLE(cpu_transcoder));
> +
> +	/* Invalidate ELD */
> +	intel_de_rmw(i915, HSW_AUD_PIN_ELD_CP_VLD,
> +		     AUDIO_ELD_VALID(cpu_transcoder), 0);
>  
>  	/*
>  	 * FIXME: We're supposed to wait for vblank here, but we have vblanks

-- 
Jani Nikula, Intel Open Source Graphics Center