[Intel-gfx] [PATCH] drm/i915: Handle disabled primary plane in debugfs i915_display_info

[Damien Lespiau]

On Mon, Jun 16, 2014 at 10:01:55AM -0700, Matt Roper wrote:
> Now that the primary plane can be disabled independently of the CRTC,
> the debugfs code needs to be updated to recognize when the primary plane
> is disabled and not try to return information about the primary plane's
> framebuffer.
> 
> This change prevents a NULL dereference when reading i915_display_info
> with a disabled primary plane.
> 
> Signed-off-by: Matt Roper <matthew.d.roper at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_debugfs.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
> index a8b8140..28aa591 100644
> --- a/drivers/gpu/drm/i915/i915_debugfs.c
> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
> @@ -2220,9 +2220,12 @@ static void intel_crtc_info(struct seq_file *m, struct intel_crtc *intel_crtc)
>  	struct drm_crtc *crtc = &intel_crtc->base;
>  	struct intel_encoder *intel_encoder;
>  
> -	seq_printf(m, "\tfb: %d, pos: %dx%d, size: %dx%d\n",
> -		   crtc->primary->fb->base.id, crtc->x, crtc->y,
> -		   crtc->primary->fb->width, crtc->primary->fb->height);
> +	if (crtc->primary->fb)
> +		seq_printf(m, "\tfb: %d, pos: %dx%d, size: %dx%d\n",
> +			   crtc->primary->fb->base.id, crtc->x, crtc->y,
> +			   crtc->primary->fb->width, crtc->primary->fb->height);
> +	else
> +		seq_printf(m, "\tprimary plane disabled\n");

seq_puts()

>  	for_each_encoder_on_crtc(dev, crtc, intel_encoder)
>  		intel_encoder_info(m, intel_crtc, intel_encoder);
>  }

-- 
Damien