On 10/24/2012 02:45 PM, Arend van Spriel wrote:
On 10/24/2012 01:14 PM, Arend van Spriel wrote:
On 10/16/2012 02:43 PM, Stanislaw Gruszka wrote:
I have this lockdep warning on wireless-testing tree based on 3.7-rc1 (no other patches except wireless bits).
============================================= Restarting tasks ... done. [ INFO: possible recursive locking detected ] 3.7.0-rc1-wl+ #2 Not tainted
Xorg/2269 is trying to acquire lock: (&cli->mutex){+.+.+.}, at: [<ffffffffa012a27f>] nouveau_bo_move_m2mf+0x5f/0x170 [nouveau]
but task is already holding lock: (&cli->mutex){+.+.+.}, at: [<ffffffffa012f3c4>] nouveau_abi16_get+0x34/0x100 [nouveau]
I have observed the same bug so I built and tested v3.7-rc2 tag with lockdep enabled. It has the same problem and it results in a failure to resume after suspend. See below.
Gr. AvS
digging into the trace:
nouveau_gem_ioctl_pushbuf() calls nouveau_abi16_get() which grabs the mutex. Assume this should protect the chan variable passed to nouveau_gem_pushbuf_validate(), which does a bit more that validate as it ends up in nouveau_bo_move_m2mf() which uses the drm->chan. However, it deadlocks before that.
Gr. AvS
I reverted the two drm merges:
ceb736c Merge branch 'drm-nouveau-fixes' of git://anongit.freedesktop.org/git/no 612a9aa Merge branch 'drm-next' of git://people.freedesktop.org/~airlied/linux
It is not surprising that it solved the deadlock (doing pm_test). Unfortunately, suspend/resume still does not work. System goes to sleep just fine, but when trying to resume the BIOS kicks in and system boots instead of waking up.
Gr. AvS