diff options
| author | Chris Wilson <chris@chris-wilson.co.uk> | 2018-03-22 07:35:32 +0000 |
|---|---|---|
| committer | Chris Wilson <chris@chris-wilson.co.uk> | 2018-03-22 20:34:46 +0000 |
| commit | 1c645bf4378f1539df57c6228f5c4957c130324a (patch) | |
| tree | cf0edb309fdf433ef127c4ef0c3260f232bb26db /drivers/gpu | |
| parent | a90507d60763ee1067cf217614a8bb2ab43aca1a (diff) | |
drm/i915: Use full serialisation around engine->irq_posted
Using engine->irq_posted for execlists, we are not always serialised by
the tasklet as we supposed. On the reset paths, the tasklet is disabled
and ignored. Instead, we manipulate the engine->irq_posted directly to
account for the reset, but if an interrupt fired before the reset and so
wrote to engine->irq_posted, that write may not be flushed from the
local CPU's cacheline until much later as the tasklet is already active
and so does not generate a mb(). To correctly serialise the interrupt
with reset, we need serialisation on the set_bit() itself.
And at last Mika can be happy.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Michał Winiarski <michal.winiarski@intel.com>
CC: Michel Thierry <michel.thierry@intel.com>
Cc: Jeff McGee <jeff.mcgee@intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Jeff McGee <jeff.mcgee@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180322073533.5313-3-chris@chris-wilson.co.uk
Diffstat (limited to 'drivers/gpu')
| -rw-r--r-- | drivers/gpu/drm/i915/i915_irq.c | 7 |
1 files changed, 3 insertions, 4 deletions
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index fa7310766217..27aee25429b7 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -1405,10 +1405,9 @@ gen8_cs_irq_handler(struct intel_engine_cs *engine, u32 iir) bool tasklet = false; if (iir & GT_CONTEXT_SWITCH_INTERRUPT) { - if (READ_ONCE(engine->execlists.active)) { - __set_bit(ENGINE_IRQ_EXECLIST, &engine->irq_posted); - tasklet = true; - } + if (READ_ONCE(engine->execlists.active)) + tasklet = !test_and_set_bit(ENGINE_IRQ_EXECLIST, + &engine->irq_posted); } if (iir & GT_RENDER_USER_INTERRUPT) { |