[Intel-gfx] [PATCH v5 5/6] drm/i915/psr: Check that vblank is long enough for psr2

[Ville Syrjälä]

On Wed, Mar 22, 2023 at 12:34:11PM +0200, Jouni Högander wrote:
> Ensure vblank >= psr2 vblank
> where
> Psr2 vblank = PSR2_CTL Block Count Number maximum line count.
> 
> Bspec: 71580, 49274
> 
> v2: Use calculated block count number maximum line count
> 
> Signed-off-by: Jouni Högander <jouni.hogander at intel.com>

Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

We seem to be also missing the "PSR2 line time" check?

> ---
>  drivers/gpu/drm/i915/display/intel_psr.c | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
> index 4b7c946a9a25..b53c71c06105 100644
> --- a/drivers/gpu/drm/i915/display/intel_psr.c
> +++ b/drivers/gpu/drm/i915/display/intel_psr.c
> @@ -968,6 +968,15 @@ static bool intel_psr2_config_valid(struct intel_dp *intel_dp,
>  		return false;
>  	}
>  
> +	/* Vblank >= PSR2_CTL Block Count Number maximum line count */
> +	if (crtc_state->hw.adjusted_mode.crtc_vblank_end -
> +	    crtc_state->hw.adjusted_mode.crtc_vblank_start <
> +	    psr2_block_count_lines(intel_dp)) {
> +		drm_dbg_kms(&dev_priv->drm,
> +			    "PSR2 not enabled, too short vblank time\n");
> +		return false;
> +	}
> +
>  	if (HAS_PSR2_SEL_FETCH(dev_priv)) {
>  		if (!intel_psr2_sel_fetch_config_valid(intel_dp, crtc_state) &&
>  		    !HAS_PSR_HW_TRACKING(dev_priv)) {
> -- 
> 2.34.1

-- 
Ville Syrjälä
Intel