[Intel-gfx] [PATCH] drm/i915: Don't clobber crtc->new_config when nothing changes

[Jesse Barnes]

On Fri, 21 Nov 2014 21:00:36 +0200
ville.syrjala at linux.intel.com wrote:

> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
> 
> When doing a nop modeset we currently leave crtc->new_config point at
> the already freed temporary pipe_config. That will anger the sanity
> checks in intel_modeset_update_state() when the nop modeset gets
> followed by a GPU reset on gen3/4 where the display block gets fully
> reinitialized during the reset.
> 
> So leave crtc->new_config alone until we know a modeset is actually
> required.
> 
> Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 8 +++++---
>  1 file changed, 5 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 853697f..3218455 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -10907,7 +10907,6 @@ intel_modeset_compute_config(struct drm_crtc *crtc,
>  	}
>  	intel_dump_pipe_config(to_intel_crtc(crtc), pipe_config,
>  			       "[modeset]");
> -	to_intel_crtc(crtc)->new_config = pipe_config;
>  
>  out:
>  	return pipe_config;
> @@ -10933,6 +10932,9 @@ static int __intel_set_mode(struct drm_crtc *crtc,
>  
>  	*saved_mode = crtc->mode;
>  
> +	if (modeset_pipes)
> +		to_intel_crtc(crtc)->new_config = pipe_config;
> +
>  	/*
>  	 * See if the config requires any additional preparation, e.g.
>  	 * to adjust global state with pipes off.  We need to do this
> @@ -11466,12 +11468,12 @@ static int intel_crtc_set_config(struct drm_mode_set *set)
>  		ret = PTR_ERR(pipe_config);
>  		goto fail;
>  	} else if (pipe_config) {
> -		if (to_intel_crtc(set->crtc)->new_config->has_audio !=
> +		if (pipe_config->has_audio !=
>  		    to_intel_crtc(set->crtc)->config.has_audio)
>  			config->mode_changed = true;
>  
>  		/* Force mode sets for any infoframe stuff */
> -		if (to_intel_crtc(set->crtc)->new_config->has_infoframe ||
> +		if (pipe_config->has_infoframe ||
>  		    to_intel_crtc(set->crtc)->config.has_infoframe)
>  			config->mode_changed = true;
>  	}

Yeah looks fine.

Reviewed-by: Jesse Barnes <jbarnes at virtuousgeek.org>

Thanks,
-- 
Jesse Barnes, Intel Open Source Technology Center