Re: 3.8-rc2: EFI framebuffer lock inversion...

On Thu, Jan 3, 2013 at 3:39 PM, Daniel J Blueman [off-list ref] wrote:

On 3 January 2013 22:11, Sedat Dilek [off-list ref] wrote:

quoted

Hi Daniel,

just wanted to test the fb-fix [2] from Alan and followed the thread in [1].
Me is also working with i915 KMS.

I looked at nouveau KMS driver and adapted the part for i915:

drivers/gpu/drm/nouveau/nouveau_drm.c-200-      /* remove conflicting
drivers (vesafb, efifb etc) */
drivers/gpu/drm/nouveau/nouveau_drm.c:201:      aper = alloc_apertures(3);
drivers/gpu/drm/nouveau/nouveau_drm.c-202-      if (!aper)
drivers/gpu/drm/nouveau/nouveau_drm.c-203-              return -ENOMEM;

Untested by me, feel free to test.

Maybe some of the i915 and/or fb driver experts can comment on the problem.

The structure array from alloc_apertures is just used for the PCI base
address registers, so it's important here.

I'll take a look at the efifb locking later.

That is the code part [1] I looked at.
Maybe the next lines with ap(er)->ranges || pci_resource_start() and
pci_resource_len() are missing?

I also looked at "include/linux/fb.h" but could not get wiser.
Also I can't say what the value "1" or "3" means in alloc_apertures().

Wouldn't it make sense to remove the conflicting fb-drivers globally
not in each affected DRM/KMS driver?
Just an idea.

- Sedat -

[1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/gpu/drm/nouveau/nouveau_drm.c;hb=refs/tags/v3.8-rc2#l192

Thanks,
  Daniel
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Daniel J Blueman