linux-stable.git/drivers/gpu/drm/drm_fops.c, branch linux-4.6.y

drm: Nuke vblank event file cleanup code

2016-02-08T08:55:47+00:00

The core code now takes care of unlinking drm_events from the file in
a generic way, so this code isn't needed any more.

For those wondering where the drm_vblank_put went to: With the new
logic events only get unlinked, but still exist. Hence any resources
(like vblank counters) don't need to be released since the event user
will still process the event normally. In this case this is the
callsites of send_vblank_event, which of course already have a
drm_vblank_put.

Cc: Laurent Pinchart 
Acked-by: Daniel Stone 
Reviewed-by: Alex Deucher 
Reviewed-by: Laurent Pinchart 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1453756616-28942-3-git-send-email-daniel.vetter@ffwll.ch

drm: Clean up pending events in the core

2016-02-08T08:55:46+00:00

There's really no reason to not do so, instead of replicating this
for every use-case and every driver. Now we can't just nuke the events,
since that would still mean that all drm_event users would need to know
when that has happened, since calling e.g. drm_send_event isn't allowed
any more. Instead just unlink them from the file, and detect this case
and handle it appropriately in all functions.

v2: Adjust existing kerneldoc too.

v3: Improve wording of the kerneldoc and split out vblank cleanup (Laurent).

Cc: Alex Deucher 
Cc: Laurent Pinchart 
Acked-by: Daniel Stone 
Reviewed-by: Alex Deucher  (v1)
Reviewed-by: Laurent Pinchart 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1453756616-28942-2-git-send-email-daniel.vetter@ffwll.ch

drm/vblank: Use drm_event_reserve_init

2016-02-08T08:54:54+00:00

Well we can't use that directly since that code must hold
dev->event_lock already. Extract an _unlocked version.

Embarrassingly I've totally forgotten about this patch and any kind of
event-based vblank wait totally blew up, killing the kernel.

v2: Pick the right base struct, someone didn't noticed that gcc was
unhappy. No bug since the addresses at least matched (Daniel Stone)

Cc: Alex Deucher 
Cc: Daniel Stone 
Cc: Laurent Pinchart 
Reviewed-by: Daniel Stone 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1453978864-1513-1-git-send-email-daniel.vetter@ffwll.ch

drm: Create drm_send_event helpers

2016-01-25T18:34:43+00:00

Use them in the core vblank code and exynos/vmwgfx drivers.

Note that the difference between wake_up_all and _interruptible in
vmwgfx doesn't matter since the only waiter is the core code in
drm_fops.c. And that is interruptible.

v2: Adjust existing kerneldoc too.

Reviewed-by: Alex Deucher  (v1)
Acked-by: Daniel Stone 
Cc: Alex Deucher 
Cc: Thomas Hellstrom 
Cc: Inki Dae 
Link: http://patchwork.freedesktop.org/patch/msgid/1452548477-15905-6-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Laurent Pinchart 
[danvet: Squash in compile fixup, spotted by 0-day.]
Signed-off-by: Daniel Vetter

drm: Add functions to setup/tear down drm_events.

2016-01-25T07:40:09+00:00

An attempt at not spreading out the file_priv->event_space stuff out
quite so far and wide.  And I think fixes something in ipp_get_event()
that is broken (or if they are doing something more weird/subtle, then
breaks it in a fun way).

Based upon a patch from Rob Clark, rebased and polished.

v2: Spelling fixes (Alex).

Cc: Alex Deucher 
Acked-by: Daniel Stone 
Reviewed-by: Alex Deucher 
Cc: Rob Clark 
Link: http://patchwork.freedesktop.org/patch/msgid/1452548477-15905-3-git-send-email-daniel.vetter@ffwll.ch
Reviewed-by: Laurent Pinchart 
Signed-off-by: Daniel Vetter

drm: kerneldoc for drm_fops.c

2016-01-25T07:39:58+00:00

Just prep work before I throw more drm_event refactorings on top.

Acked-by: Daniel Stone 
Reviewed-by: Alex Deucher 
Link: http://patchwork.freedesktop.org/patch/msgid/1452548477-15905-2-git-send-email-daniel.vetter@ffwll.ch
Signed-off-by: Daniel Vetter

Back merge tag 'v4.4-rc4' into drm-next

2015-12-08T01:04:26+00:00

We've picked up a few conflicts and it would be nice
to resolve them before we move onwards.

drm: Fix an unwanted master inheritance v2

2015-12-04T02:28:14+00:00

A client calling drmSetMaster() using a file descriptor that was opened
when another client was master would inherit the latter client's master
object and all its authenticated clients.

This is unwanted behaviour, and when this happens, instead allocate a
brand new master object for the client calling drmSetMaster().

Fixes a BUG() throw in vmw_master_set().

Cc: 
Signed-off-by: Thomas Hellstrom 
Signed-off-by: Dave Airlie

drm: Serialise multiple event readers

2015-11-26T14:21:27+00:00

The previous patch reintroduced a race condition whereby a failure in
one reader may allow a second reader to see out-of-order events.
Introduce a mutex to serialise readers so that an event is completed in
its entirety before another reader may process an event. The two readers
may race against each other, but the events each retrieves are in the
correct order.

Signed-off-by: Chris Wilson 
Cc: Thomas Hellstrom 
Cc: Takashi Iwai 
Cc: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1448462343-2072-2-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Thomas Hellstrom 
Signed-off-by: Daniel Vetter

drm: Drop dev->event_lock spinlock around faulting copy_to_user()

2015-11-26T14:21:06+00:00

In

commit cdd1cf799bd24ac0a4184549601ae302267301c5
Author: Chris Wilson 
Date:   Thu Dec 4 21:03:25 2014 +0000

    drm: Make drm_read() more robust against multithreaded races

I fixed the races by serialising the use of the event by extending the
dev->event_lock. However, as Thomas pointed out, the copy_to_user() may
fault (even the __copy_to_user_inatomic() variant used here) and calling
into the driver backend with the spinlock held is bad news. Therefore we
have to drop the spinlock before the copy, but that exposes us to the
old race whereby a second reader could see an out-of-order event (as the
first reader may claim the first request but fail to copy it back to
userspace and so on returning it to the event list it will be behind the
current event being copied by the second reader).

Reported-by: Thomas Hellstrom 
Signed-off-by: Chris Wilson 
Cc: Thomas Hellstrom 
Cc: Takashi Iwai 
Cc: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/1448462343-2072-1-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Thomas Hellstrom 
Signed-off-by: Daniel Vetter