Some urgent regression fixes to booting failures Exynos DRM occured.
Summary:
- Fix two urgent null pointer dereference bugs in case of enabling
or disabling IOMMU. There was two cases to these issues.
One is that plane->crtc is accessed by exynos_disable_plane()
when device tree binding is broken so device driver tries
to release, which means that the mode set operation isn't invoked yet
so plane->crtc is still NULL and exynos_disable_plane() will access
NULL pointer. This issue is fixed by checking if the plane->crtc
is NULL or not in exynos_disable_plane()
Other is that fimd_wait_for_vblank() is called to avoid from page fault
with IOMMU before the ctx object is created. At this time,
fimd_wait_for_vblank() tries to access ctx->crtc but the ctx->crtc
is still NULL because exynos_drm_crtc_create() isn't called yet.
This issue is fixed by creating a crtc object and setting it to
ctx->crtc prior to fimd_wait_for_vblank() call.
For more details, you can refer to below an e-mail thread,
http://www.spinics.net/lists/linux-samsung-soc/msg42436.html
- Remove unnecessary file not used and fix trivial issues.
* 'exynos-drm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/daeinki/drm-exynos:
drm/exynos: fix the initialization order in FIMD
drm/exynos: fix typo config name correctly.
drm/exynos: Check for NULL dereference of crtc
drm/exynos: IS_ERR() vs NULL bug
drm/exynos: remove unused files