[Intel-gfx] [PATCH] drm/i915/audio: fix compressed_bpp check

[Shankar, Uma]

> -----Original Message-----
> From: Jani Nikula <jani.nikula at intel.com>
> Sent: Monday, April 20, 2020 6:47 PM
> To: intel-gfx at lists.freedesktop.org
> Cc: Nikula, Jani <jani.nikula at intel.com>; Gupta, Anshuman
> <anshuman.gupta at intel.com>; Shankar, Uma <uma.shankar at intel.com>
> Subject: [PATCH] drm/i915/audio: fix compressed_bpp check
> 
> The early check for compressed_bpp being zero is too early, as it is hit also when
> DSC is not enabled. Move the checks down to where the values are actually needed.
> This is a paranoid check for a situation that should not happen, so we don't really
> care about handling it gracefully apart from not oopsing.

Looks Good to me. Thanks Jani.
Reviewed-by: Uma Shankar <uma.shankar at intel.com>

> Fixes: 48b8b04c791d ("drm/i915/display: Enable DP Display Audio WA")
> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1750
> Cc: Anshuman Gupta <anshuman.gupta at intel.com>
> Cc: Uma Shankar <uma.shankar at intel.com>
> Signed-off-by: Jani Nikula <jani.nikula at intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_audio.c | 15 +++++----------
>  1 file changed, 5 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_audio.c
> b/drivers/gpu/drm/i915/display/intel_audio.c
> index 2663e71059af..36aaee8536f1 100644
> --- a/drivers/gpu/drm/i915/display/intel_audio.c
> +++ b/drivers/gpu/drm/i915/display/intel_audio.c
> @@ -542,6 +542,10 @@ static unsigned int get_hblank_early_enable_config(struct
> intel_encoder *encoder
>  		    h_active, crtc_state->port_clock, crtc_state->lane_count,
>  		    vdsc_bpp, cdclk);
> 
> +	if (WARN_ON(!crtc_state->port_clock || !crtc_state->lane_count ||
> +		    !crtc_state->dsc.compressed_bpp || !i915->cdclk.hw.cdclk))
> +		return 0;
> +
>  	link_clks_available = ((((h_total - h_active) *
>  			       ((crtc_state->port_clock * ROUNDING_FACTOR) /
>  				pixel_clk)) / ROUNDING_FACTOR) - 28); @@ -
> 597,21 +601,12 @@ static void enable_audio_dsc_wa(struct intel_encoder
> *encoder,
>  	struct drm_i915_private *i915 = to_i915(encoder->base.dev);
>  	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
>  	enum pipe pipe = crtc->pipe;
> -	unsigned int hblank_early_prog, samples_room, h_active;
> +	unsigned int hblank_early_prog, samples_room;
>  	unsigned int val;
> 
>  	if (INTEL_GEN(i915) < 11)
>  		return;
> 
> -	h_active = crtc_state->hw.adjusted_mode.hdisplay;
> -
> -	if (!(h_active && crtc_state->port_clock && crtc_state->lane_count &&
> -	      crtc_state->dsc.compressed_bpp && i915->cdclk.hw.cdclk)) {
> -		drm_err(&i915->drm, "Null Params rcvd for hblank early
> enabling\n");
> -		WARN_ON(1);
> -		return;
> -	}
> -
>  	val = intel_de_read(i915, AUD_CONFIG_BE);
> 
>  	if (INTEL_GEN(i915) == 11)
> --
> 2.20.1