linux-toradex.git/drivers/gpu/drm/drm_plane.c, branch v4.12

drm: Fix deadlock retry loop in page_flip_ioctl

2017-05-23T07:39:14+00:00

I failed to properly onion-wrap the unwind code: We acquire the vblank
reference before we start with the wait-wound locking dance, hence we
must make sure we retry before we drop the reference. Oops.

v2: The vblank_put must be after the frambuffer_put (Michel). I suck at
unwrapping code that doesn't use separate labels for each stage, but
checks each pointer first ... While re-reading everything I also
realized that we must clean up the fb refcounts, and specifically
plane->old_fb before we drop the locks, either in the final unlocking,
or in the w/w retry path. Hence the correct fix is to drop the
vblank_put to the very bottom.

Fixes: 29dc0d1de182 ("drm: Roll out acquire context for the page_flip ioctl")
Cc: Harry Wentland 
Cc: Daniel Vetter 
Cc: Jani Nikula 
Cc: Sean Paul 
Cc: David Airlie 
Cc: dri-devel@lists.freedesktop.org
Reported-by: Tommi Rantala 
Cc: Tommi Rantala 
Cc: Michel Dänzer 
Tested-by: Tommi Rantala 
Reviewed-by: Michel Dänzer 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170522135945.28831-1-daniel.vetter@ffwll.ch

drm: Only take cursor locks when the cursor plane exists

2017-04-07T17:28:32+00:00

I thought I've fixed this, but maybe not. Anyway, clearly broken, and
easy fix.

Cc: Tony Lindgren 
Reported-by: Tony Lindgren 
Fixes: b95ff0319a82 ("drm: Remove drm_modeset_(un)lock_crtc")
Cc: Harry Wentland 
Cc: Maarten Lankhorst 
Cc: Daniel Vetter 
Cc: Jani Nikula 
Cc: Sean Paul 
Cc: David Airlie 
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter 
Tested-by: Tony Lindgren 
Reviewed-by: Daniel Stone 
Signed-off-by: Sean Paul 
Link: http://patchwork.freedesktop.org/patch/msgid/20170407164817.28272-1-daniel.vetter@ffwll.ch

drm: Remove drm_modeset_(un)lock_crtc

2017-04-05T07:26:07+00:00

The last user, the cursor ioctl, can just open-code this too. We
simply have to move the acquire ctx dance from the universal function
up into the top-level ioctl handler.

Reviewed-by: Harry Wentland 
Reviewed-by: Maarten Lankhorst 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170403083304.9083-3-daniel.vetter@ffwll.ch

drm: Fix locking gotcha in page_flip ioctl

2017-03-31T00:28:24+00:00

We want to lock the primary plane, not the cursor (which might be
optional). Real bad case of copy-paste fail, unfortunately our CI
didn't catch that because i915 does have a cursor plane.

Reported-by: Eric Anholt 
Fixes: 29dc0d1de182 ("drm: Roll out acquire context for the page_flip ioctl")
Cc: Jani Nikula 
Cc: Sean Paul 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170330204831.8225-1-daniel.vetter@ffwll.ch
Tested-by: Eric Anholt 
Reviewed-by: Harry Wentland

drm: Clear e after kfree in drm_mode_page_flip_ioctl

2017-03-30T18:23:51+00:00

With the explicit retry loop static analyzers get confused by the
control flow and believe that e could be accessed after kfree. That's
not possible, but it's non-obvious, so let's clear it to NULL.

We already cleared e = NULL at the top of the function, so this is all
in line.

Cc: Julia Lawall 
Reported-by: Julia Lawall 
Fixes: 29dc0d1de182 ("drm: Roll out acquire context for the page_flip ioctl")
Cc: Harry Wentland 
Cc: Daniel Vetter 
Cc: Jani Nikula 
Cc: Sean Paul 
Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170330133253.29500-1-daniel.vetter@ffwll.ch

drm/atomic-helper: remove backoff hack from page_flip

2017-03-29T07:50:52+00:00

Yay, we can now properly retry in case of deadlocks or whatever!

Also don't forget to remove the transitional crtc->acquire_ctx
assignment again.

Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-13-daniel.vetter@ffwll.ch

drm: Add acquire ctx parameter to ->page_flip(_target)

2017-03-29T07:50:38+00:00

Again just going through the motions, no functional changes in here.

Cc: Gerd Hoffmann 
Cc: Ben Skeggs 
Cc: Russell King 
Cc: Laurent Pinchart 
Cc: Eric Anholt 
Cc: Alex Deucher 
Cc: Christian König 
Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter t
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-12-daniel.vetter@ffwll.ch

drm: Roll out acquire context for the page_flip ioctl

2017-03-29T07:50:07+00:00

Again just prep work.

Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-11-daniel.vetter@ffwll.ch

drm/atomic-helper: remove backoff hack from disable/update_plane

2017-03-29T07:15:06+00:00

We can now properly retry at the top level, yay!

v2: Also remove the temporary acquire_ctx hack again, no longer
needed!

Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-6-daniel.vetter@ffwll.ch

drm: Add acquire ctx parameter to ->plane_disable

2017-03-29T07:14:58+00:00

Nouveau had a few direct calls to ->disable_plane, I replaced those
with drm_plane_force_disable. Same story for shmob.

Otherwise no code changes.

Cc: Ben Skeggs 
Cc: Russell King 
Cc: Laurent Pinchart 
Reviewed-by: Harry Wentland 
Signed-off-by: Daniel Vetter 
Link: http://patchwork.freedesktop.org/patch/msgid/20170322215058.8671-5-daniel.vetter@ffwll.ch