drm/cirrus: Use drm_framebuffer_put to avoid kernel oops in clean-up

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In the Cirrus driver, the regular clean-up code also performs the clean-up
of a failed initialization. If the fbdev's framebuffer was not initialized,
the clean-up will fail within drm_framebuffer_unregister_private. Booting
with cirrus.bpp=16 triggers this bug.

The framebuffer is currently stored directly within struct cirrus_fbdev. To
fix the bug, we turn it into a pointer that is only set for initialized
framebuffers. The fbdev's clean-up code skips uninitialized framebuffers.

The memory for struct drm_framebuffer is allocated dynamically. This requires
additional error handling within cirrusfb_create. The framebuffer clean-up is
now performed by drm_framebuffer_put, which also frees the data strcuture's
memory.

Link: https://bugzilla.suse.com/show_bug.cgi?id=1101822
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: http://patchwork.freedesktop.org/patch/msgid/20180720112743.27159-1-tzimmermann@suse.de
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

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This commit is contained in:

Thomas Zimmermann 2018-07-20 13:27:43 +02:00 • committed by Gerd Hoffmann

parent f82aab2d52

commit abf7b30d7f

3 changed files with 29 additions and 23 deletions

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2

drivers/gpu/drm/cirrus/cirrus_drv.h

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48

drivers/gpu/drm/cirrus/cirrus_fbdev.c

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2

drivers/gpu/drm/cirrus/cirrus_mode.c

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