linux/drivers/gpu
Maxime Ripard f2df84e096
drm/vc4: kms: Store the unassigned channel list in the state
If a CRTC is enabled but not active, and that we're then doing a page
flip on another CRTC, drm_atomic_get_crtc_state will bring the first
CRTC state into the global state, and will make us wait for its vblank
as well, even though that might never occur.

Instead of creating the list of the free channels each time atomic_check
is called, and calling drm_atomic_get_crtc_state to retrieve the
allocated channels, let's create a private state object in the main
atomic state, and use it to store the available channels.

Since vc4 has a semaphore (with a value of 1, so a lock) in its commit
implementation to serialize all the commits, even the nonblocking ones, we
are free from the use-after-free race if two subsequent commits are not ran
in their submission order.

Fixes: 87ebcd42fb ("drm/vc4: crtc: Assign output to channel automatically")
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Tested-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Reviewed-by: Hoegeun Kwon <hoegeun.kwon@samsung.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20201120144245.398711-2-maxime@cerno.tech
2020-11-23 17:59:23 +01:00
..
drm drm/vc4: kms: Store the unassigned channel list in the state 2020-11-23 17:59:23 +01:00
host1x drm next for 5.10-rc1 2020-10-15 10:46:16 -07:00
ipu-v3 treewide: Use fallthrough pseudo-keyword 2020-08-23 17:36:59 -05:00
trace
vga vgaarb: mark vga_tryget static 2020-08-01 11:28:17 +02:00
Makefile