[Intel-gfx] [PATCH] drm/i915: Discard BIOS framebuffers too small to accommodate chosen mode

[Jani Nikula]

On Wed, 23 Apr 2014, Ville Syrjälä <ville.syrjala at linux.intel.com> wrote:
> On Wed, Apr 23, 2014 at 08:54:31AM +0100, Chris Wilson wrote:
>> If the inherited BIOS framebuffer is smaller than the mode selected for
>> fbdev, then if we continue to use it then we cause display corruption as
>> we do not setup the panel fitter to upscale.
>> 
>> Regression from commit d978ef14456a38034f6c0e94a794129501f89200
>> Author: Jesse Barnes <jbarnes at virtuousgeek.org>
>> Date:   Fri Mar 7 08:57:51 2014 -0800
>> 
>>     drm/i915: Wrap the preallocated BIOS framebuffer and preserve for KMS fbcon v12
>> 
>> v2: Add a debug message to track the discard of the BIOS fb.
>> v3: Ville pointed out the difference between ref/unref
>> 
>> Reported-by: Knut Petersen <Knut_Petersen at t-online.de>
>> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=77767
>> Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> Cc: Jesse Barnes <jbarnes at virtuousgeek.org>
>> Reviewed-by: Daniel Vetter <daniel.vetter at ffwll.ch>
>
> Reviewed-by: Ville Syrjälä <ville.syrjala at linux.intel.com>

Pushed to -fixes, thanks for the patch and review.

BR,
Jani.


>
>> ---
>>  drivers/gpu/drm/i915/intel_fbdev.c | 10 ++++++++++
>>  1 file changed, 10 insertions(+)
>> 
>> diff --git a/drivers/gpu/drm/i915/intel_fbdev.c b/drivers/gpu/drm/i915/intel_fbdev.c
>> index b16116db6c37..fbe7941f88c8 100644
>> --- a/drivers/gpu/drm/i915/intel_fbdev.c
>> +++ b/drivers/gpu/drm/i915/intel_fbdev.c
>> @@ -133,6 +133,16 @@ static int intelfb_create(struct drm_fb_helper *helper,
>>  
>>  	mutex_lock(&dev->struct_mutex);
>>  
>> +	if (intel_fb &&
>> +	    (sizes->fb_width > intel_fb->base.width ||
>> +	     sizes->fb_height > intel_fb->base.height)) {
>> +		DRM_DEBUG_KMS("BIOS fb too small (%dx%d), we require (%dx%d),"
>> +			      " releasing it\n",
>> +			      intel_fb->base.width, intel_fb->base.height,
>> +			      sizes->fb_width, sizes->fb_height);
>> +		drm_framebuffer_unreference(&intel_fb->base);
>> +		intel_fb = ifbdev->fb = NULL;
>> +	}
>>  	if (!intel_fb || WARN_ON(!intel_fb->obj)) {
>>  		DRM_DEBUG_KMS("no BIOS fb, allocating a new one\n");
>>  		ret = intelfb_alloc(helper, sizes);
>> -- 
>> 1.9.2
>> 
>> _______________________________________________
>> Intel-gfx mailing list
>> Intel-gfx at lists.freedesktop.org
>> http://lists.freedesktop.org/mailman/listinfo/intel-gfx
>
> -- 
> Ville Syrjälä
> Intel OTC
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-- 
Jani Nikula, Intel Open Source Technology Center