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| author | Chris Wilson <chris@chris-wilson.co.uk> | 2018-03-07 13:42:26 +0000 |
|---|---|---|
| committer | Joonas Lahtinen <joonas.lahtinen@linux.intel.com> | 2018-03-16 14:35:35 +0200 |
| commit | 73e2232aa3253d77935112bfc218700f6a2f1000 (patch) | |
| tree | e7cd5ca947a0e1df1bd4e1ef8abdb794945a2e3c /drivers/gpu/drm/i915/i915_gem.c | |
| parent | 7e9d3a4a1b21fd8a595774697f4047e7505deea6 (diff) | |
| download | linux-73e2232aa3253d77935112bfc218700f6a2f1000.tar.bz2 | |
drm/i915: Only call tasklet_kill() on the first prepare_reset
tasklet_kill() will spin waiting for the current tasklet to be executed.
However, if tasklet_disable() has been called, then the tasklet is never
executed but permanently put back onto the runlist until
tasklet_enable() is called. Ergo, we cannot use tasklet_kill() inside a
disable/enable pair. This is the case when we call set-wedge from inside
i915_reset(), and another request was submitted to us concurrent to the
reset.
Fixes: 963ddd63c314 ("drm/i915: Suspend submission tasklets around wedging")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180307134226.25492-6-chris@chris-wilson.co.uk
(cherry picked from commit 68ad361285a9cc73b259f59adbaafde196c15987)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/i915_gem.c')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_gem.c | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c index 8d913d833ab9..0359d6f870b4 100644 --- a/drivers/gpu/drm/i915/i915_gem.c +++ b/drivers/gpu/drm/i915/i915_gem.c @@ -2940,8 +2940,16 @@ i915_gem_reset_prepare_engine(struct intel_engine_cs *engine) * calling engine->init_hw() and also writing the ELSP. * Turning off the execlists->tasklet until the reset is over * prevents the race. + * + * Note that this needs to be a single atomic operation on the + * tasklet (flush existing tasks, prevent new tasks) to prevent + * a race between reset and set-wedged. It is not, so we do the best + * we can atm and make sure we don't lock the machine up in the more + * common case of recursively being called from set-wedged from inside + * i915_reset. */ - tasklet_kill(&engine->execlists.tasklet); + if (!atomic_read(&engine->execlists.tasklet.count)) + tasklet_kill(&engine->execlists.tasklet); tasklet_disable(&engine->execlists.tasklet); /* |