AuxXxilium/linux_dsm_epyc7002
1
0
Fork 0
mirror of https://github.com/AuxXxilium/linux_dsm_epyc7002.git synced 2025-03-10 12:03:39 +07:00
Code Issues Actions Packages Projects Releases Wiki Activity
f59bcca620
linux_dsm_epyc7002/include
History
Daniel Vetter 75426367cd drm/ioctl: Ditch DRM_UNLOCKED except for the legacy vblank ioctl 
This completes Emil's series of removing DRM_UNLOCKED from modern
drivers. It's entirely cargo-culted since we ignore it on
non-DRIVER_LEGACY drivers since:

commit ea487835e8
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Mon Sep 28 21:42:40 2015 +0200

    drm: Enforce unlocked ioctl operation for kms driver ioctls

Now justifying why we can do this for legacy drives too (and hence
close the source of all the bogus copypasting) is a bit more involved.
DRM_UNLOCKED was introduced in:

commit ed8b670409
Author: Arnd Bergmann <arnd@arndb.de>
Date:   Wed Dec 16 22:17:09 2009 +0000

    drm: convert drm_ioctl to unlocked_ioctl

As a immediate hack to keep i810 happy, which would have deadlocked
without this trickery. The old BKL is automatically dropped in
schedule(), and hence the i810 vs. mmap_sem deadlock didn't actually
cause a real deadlock. But with a mutex it would. The solution was to
annotate these as DRM_UNLOCKED and mark i810 unsafe on SMP machines.

This conversion caused a regression, because unlike the BKL a mutex
isn't dropped over schedule (that thing again), which caused a vblank
wait in one thread to block the entire desktop and all its apps. Back
then we did vblank scheduling by blocking in the client, awesome isn't
it. This was fixed quickly in (ok not so quickly, took 2 years):

commit 8f4ff2b06a
Author: Ilija Hadzic <ihadzic@research.bell-labs.com>
Date:   Mon Oct 31 17:46:18 2011 -0400

    drm: do not sleep on vblank while holding a mutex

All the other DRM_UNLOCKED annotations for all the core ioctls was
work to reach finer-grained locking for modern drivers. This took
years, and culminated in:

commit fdd5b877e9
Author: Daniel Vetter <daniel.vetter@ffwll.ch>
Date:   Sat Dec 10 22:52:54 2016 +0100

    drm: Enforce BKL-less ioctls for modern drivers

DRM_UNLOCKED was never required by any legacy drivers, except for the
vblank_wait IOCTL. Therefore we will not regress these old drivers by
going back to where we've been in 2011. For all modern drivers nothing
will change.

To make this perfectly clear, also add a comment to DRM_UNLOCKED.

v2: Don't forget about drm_ioc32.c (Michel).

Cc: Michel Dänzer <michel@daenzer.net>
Cc: Emil Velikov <emil.l.velikov@gmail.com>
Acked-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Michel Dänzer <michel@daenzer.net>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190605120835.2798-1-daniel.vetter@ffwll.ch
2019-06-21 19:13:10 +02:00
..
acpi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
asm-generic treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
clocksource treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
crypto treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335 2019-06-05 17:37:06 +02:00
drm drm/ioctl: Ditch DRM_UNLOCKED except for the legacy vblank ioctl 2019-06-21 19:13:10 +02:00
dt-bindings treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 446 2019-06-05 17:37:18 +02:00
keys treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441 2019-06-05 17:37:17 +02:00
kvm treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 342 2019-06-05 17:37:07 +02:00
linux Merge branch 'topic/remove-fbcon-notifiers' into drm-misc-next 2019-06-19 12:33:05 +02:00
math-emu math-emu: Use statement expressions to fix Wshift-count-overflow warning 2019-05-31 15:23:25 +08:00
media treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 316 2019-06-05 17:37:05 +02:00
memory
misc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 152 2019-05-30 11:26:32 -07:00
net SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
pcmcia
ras
rdma SPDX update for 5.2-rc4 2019-06-08 12:52:42 -07:00
scsi treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 335 2019-06-05 17:37:06 +02:00
soc treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 399 2019-06-05 17:37:12 +02:00
sound sound fixes for 5.2-rc5 2019-06-14 05:37:06 -10:00
target
trace treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 284 2019-06-05 17:36:37 +02:00
uapi Merge remote-tracking branch 'drm/drm-next' into drm-misc-next 2019-06-19 12:32:13 +02:00
video treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 428 2019-06-05 17:37:16 +02:00
xen