[Intel-gfx] [PATCH 2/5] drm/i915: Clear most of crtc state when disabling the crtc

[Souza, Jose]

On Wed, 2020-01-15 at 21:08 +0200, Ville Syrjala wrote:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> Currently we don't call intel_crtc_prepare_cleared_state() for crtcs
> that are going to be entirely disabled (uapi.enable==false). That
> means such crtcs will leave state junk lying around in their states
> and we have to sprinkle hw.enable checks all over before we can
> look at the states. Let's change that a bit so that we aways do
> the state clearing, even for fully disabled crtcs.
> 
> Note that we still keep some parts of the old state (see
> intel_crtc_prepare_cleared_state() for the details) so probably
> can't trust things 100% when hw.enable==false. But at least there's
> less chance now that we end up looking at stale junk.
> 

Reviewed-by: José Roberto de Souza <jose.souza at intel.com>

> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/display/intel_display.c | 8 +++-----
>  1 file changed, 3 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/display/intel_display.c
> b/drivers/gpu/drm/i915/display/intel_display.c
> index b397816ce253..e68af024e13c 100644
> --- a/drivers/gpu/drm/i915/display/intel_display.c
> +++ b/drivers/gpu/drm/i915/display/intel_display.c
> @@ -14607,15 +14607,13 @@ static int intel_atomic_check(struct
> drm_device *dev,
>  			continue;
>  		}
>  
> -		if (!new_crtc_state->uapi.enable) {
> -			intel_crtc_copy_uapi_to_hw_state(new_crtc_state
> );
> -			continue;
> -		}
> -
>  		ret = intel_crtc_prepare_cleared_state(new_crtc_state);
>  		if (ret)
>  			goto fail;
>  
> +		if (!new_crtc_state->hw.enable)
> +			continue;
> +
>  		ret = intel_modeset_pipe_config(new_crtc_state);
>  		if (ret)
>  			goto fail;