linux_dsm_epyc7002/drivers/gpu
Hans de Goede 9b61db1aed drm: gm12u320: Do not take a mutex from a wait_event condition
I made the condition of the wait_event_timeout call in
gm12u320_fb_update_work a helper which takes a mutex to make sure
that any writes to fb_update.run or fb_update.fb from other CPU cores
are seen before the check is done.

This is not necessary as the wait_event helpers contain the necessary
barriers for this themselves.

More over it is harmfull since by the time the check is done the task
is no longer in the TASK_RUNNING state and calling mutex_lock while not
in task-running is not allowed, leading to this warning when the kernel
is build with some extra locking checks enabled:

[11947.450011] do not call blocking ops when !TASK_RUNNING; state=2 set at
               [<00000000e4306de6>] prepare_to_wait_event+0x61/0x190

This commit fixes this by dropping the helper and simply directly
checking the condition (without unnecessary locking) in the
wait_event_timeout call.

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190811143725.5951-1-hdegoede@redhat.com
2019-08-12 21:30:20 +02:00
..
drm drm: gm12u320: Do not take a mutex from a wait_event condition 2019-08-12 21:30:20 +02:00
host1x drm/tegra: Changes for v5.3-rc1 2019-06-25 12:59:43 +10:00
ipu-v3 drm main pull request for v5.3-rc1 (sans mm changes) 2019-07-15 19:04:27 -07:00
vga topic/remove-fbcon-notifiers: 2019-06-26 12:26:34 +02:00
Makefile treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00