[Intel-gfx] [PATCH 6/5] drm/i915: Make sure the primary plane is enabled before reading out the fb state

[Matt Roper]

On Thu, Feb 05, 2015 at 07:35:13PM +0000, Damien Lespiau wrote:
> We don't want to end up in a state where we track that the pipe has its
> primary plane enabled when primary plane registers are programmed with
> values that look possible but the plane actually disabled.
> 
> Refuse to read out the fb state when the primary plane isn't enabled.
> 
> Suggested-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> Suggested-by: Matt Roper <matthew.d.roper at intel.com>
> Signed-off-by: Damien Lespiau <damien.lespiau at intel.com>

For the series:

Reviewed-by: Matt Roper <matthew.d.roper at intel.com>

> ---
>  drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++----
>  1 file changed, 11 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 074f204..3fe9598 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -6613,6 +6613,10 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc,
>  	struct drm_framebuffer *fb;
>  	struct intel_framebuffer *intel_fb;
>  
> +	val = I915_READ(DSPCNTR(plane));
> +	if (!(val & DISPLAY_PLANE_ENABLE))
> +		return;
> +
>  	intel_fb = kzalloc(sizeof(*intel_fb), GFP_KERNEL);
>  	if (!intel_fb) {
>  		DRM_DEBUG_KMS("failed to alloc fb\n");
> @@ -6621,8 +6625,6 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc,
>  
>  	fb = &intel_fb->base;
>  
> -	val = I915_READ(DSPCNTR(plane));
> -
>  	if (INTEL_INFO(dev)->gen >= 4)
>  		if (val & DISPPLANE_TILED)
>  			plane_config->tiling = I915_TILING_X;
> @@ -7654,6 +7656,9 @@ skylake_get_initial_plane_config(struct intel_crtc *crtc,
>  	fb = &intel_fb->base;
>  
>  	val = I915_READ(PLANE_CTL(pipe, 0));
> +	if (!(val & PLANE_CTL_ENABLE))
> +		goto error;
> +
>  	if (val & PLANE_CTL_TILED_MASK)
>  		plane_config->tiling = I915_TILING_X;
>  
> @@ -7741,6 +7746,10 @@ ironlake_get_initial_plane_config(struct intel_crtc *crtc,
>  	struct drm_framebuffer *fb;
>  	struct intel_framebuffer *intel_fb;
>  
> +	val = I915_READ(DSPCNTR(pipe));
> +	if (!(val & DISPLAY_PLANE_ENABLE))
> +		return;
> +
>  	intel_fb = kzalloc(sizeof(*intel_fb), GFP_KERNEL);
>  	if (!intel_fb) {
>  		DRM_DEBUG_KMS("failed to alloc fb\n");
> @@ -7749,8 +7758,6 @@ ironlake_get_initial_plane_config(struct intel_crtc *crtc,
>  
>  	fb = &intel_fb->base;
>  
> -	val = I915_READ(DSPCNTR(pipe));
> -
>  	if (INTEL_INFO(dev)->gen >= 4)
>  		if (val & DISPPLANE_TILED)
>  			plane_config->tiling = I915_TILING_X;
> -- 
> 1.8.3.1
> 

-- 
Matt Roper
Graphics Software Engineer
IoTG Platform Enabling & Development
Intel Corporation
(916) 356-2795