bianbu-linux-6.6/drivers/gpu
Daniel Vetter 1b11629737 drm: Drop grab fpriv->fbs_lock in drm_fb_release
Paulo Zanoni reported a lockdep splat with a locking inversion between
fpriv->fbs_lock and the modeset locks. This issue was introduced in

commit f2b50c1161
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Fri Sep 12 17:07:32 2014 +0200

    drm: Fixup locking for universal cursor planes

This here is actually one of the rare cases where lockdep hits a false
positive: The deadlock only happens in drm_fb_release, which cleans up
the file private structure when all the references are gone. So the
locking is the very last one and no one else can deadlock. It also
doesn't protect anything at all, since all ioctls are guaranteed to
have returned at this point - otherwise they'd still hold a reference
on the file.

So let's just drop it and replace it with a big comment.

Cc: David Herrmann <dh.herrmann@gmail.com>
Cc: Matt Roper <matthew.d.roper@intel.com>
Cc: Paulo Zanoni <przanoni@gmail.com>
Reported-and-Tested-by: Paulo Zanoni <przanoni@gmail.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
2014-09-25 17:13:40 +02:00
..
drm drm: Drop grab fpriv->fbs_lock in drm_fb_release 2014-09-25 17:13:40 +02:00
host1x drm/tegra: Make job submission 64-bit safe 2014-08-04 10:07:36 +02:00
ipu-v3 gpu: ipu-v3: Add ipu_dump() 2014-09-02 14:55:56 +02:00
vga vgaarb: We can own non-decoded resources 2014-07-08 11:15:09 +10:00
Makefile gpu: ipu-v3: Move i.MX IPUv3 core driver out of staging 2014-06-04 11:06:52 +02:00