linux_dsm_epyc7002/drivers/gpu
Stanislav Lisovskiy 23d8003907 drm/dp_mst: Check if primary mstb is null
Unfortunately drm_dp_get_mst_branch_device which is called from both
drm_dp_mst_handle_down_rep and drm_dp_mst_handle_up_rep seem to rely
on that mgr->mst_primary is not NULL, which seem to be wrong as it can be
cleared with simultaneous mode set, if probing fails or in other case.
mgr->lock mutex doesn't protect against that as it might just get
assigned to NULL right before, not simultaneously.

There are currently bugs 107738, 108616 bugs which crash in
drm_dp_get_mst_branch_device, caused by this issue.

v2: Refactored the code, as it was nicely noticed.
    Fixed Bugzilla bug numbers(second was 108616, but not 108816)
    and added links.

[changed title and added stable cc]
Signed-off-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Cc: stable@vger.kernel.org
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=108616
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=107738
Link: https://patchwork.freedesktop.org/patch/msgid/20181109090012.24438-1-stanislav.lisovskiy@intel.com
2018-11-09 12:27:25 -05:00
..
drm drm/dp_mst: Check if primary mstb is null 2018-11-09 12:27:25 -05:00
host1x gpu: host1x: Detach Host1x from IOMMU DMA domain on arm32 2018-09-26 17:11:14 +02:00
ipu-v3 media: v4l: mediabus: Recognise CSI-2 D-PHY and C-PHY 2018-10-04 16:06:15 -04:00
vga ALSA: hda - Enable runtime PM only for discrete GPU 2018-09-13 17:58:30 +02:00
Makefile