From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Wed, 16 May 2018 19:33:48 +0100
Subject: drm/i915: Remove tasklet flush before disable
Git-commit: b8444cf85b629413ad23f5b6ed9bf5267f38acab
Patch-mainline: v4.19-rc1
References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166
The idea was to try and let the existing tasklet run to completion
before we began the reset, but it involves a racy check against anything
else that tries to run the tasklet. Rather than acknowledge and ignore
the race, let it be and don't try and be too clever.
The tasklet will resume execution after reset (after spinning a bit
during reset), but before we allow it to resume we will have cleared all
the pending state.
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/20180516183355.10553-1-chris@chris-wilson.co.uk
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
drivers/gpu/drm/i915/i915_gem.c | 9 ---------
1 file changed, 9 deletions(-)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -3062,16 +3062,7 @@ i915_gem_reset_prepare_engine(struct int
* 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.
*/
- if (!atomic_read(&engine->execlists.tasklet.count))
- tasklet_kill(&engine->execlists.tasklet);
tasklet_disable(&engine->execlists.tasklet);
/*