[Intel-gfx] [PATCH] drm/i915: Use the first mode if there is no preferred mode in the EDID

[Chris Wilson]

On Tue, May 13, 2014 at 04:07:37PM +0100, Chris Wilson wrote:
> This matches the algorithm used by earlier kernels when selecting the
> mode for the fbcon. And only if there is no modes at all, do we fall
> back to using the BIOS configuration. Seamless transition is still
> preserved (from the BIOS configuration to ours) so long as the BIOS has
> also chosen what we hope is the native configuration.
> 
> Reported-by: Knut Petersen <Knut_Petersen at t-online.de>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=78655
> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> Cc: stable at vger.kernel.org
> ---
>  drivers/gpu/drm/i915/intel_fbdev.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
> index 1d3f0a9cce31..05beec4badd5 100644
> --- a/drivers/gpu/drm/i915/intel_fbdev.c
> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
> @@ -397,6 +397,14 @@ static bool intel_fb_initial_config(struct drm_fb_helper *fb_helper,
>  							  height);
>  		}
>  
> +		/* No preferred mode marked by the EDID? Are there any modes? */
> +		if (!modes[i] && !list_empty(&connector->modes)) {
> +			DRM_DEBUG_KMS("using first mode listed on connector %s\n",
> +				      drm_get_connector_name(connector));
> +			modes[i] = list_first_entry(struct drm_display_mode,
> +						    &connector->modes, head);

Please imagine that I wrote this correctly.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre