The irq_lock is acquired in multiple functions:
1) i915_request_cancel_breadcrumb
<- ... <- panfrost_gpu_irq_handler
2) intel_engine_breadcrumbs_irq
<- ... <- cherryview_irq_handler
3) i915_request_enable_breadcrumb
4) virtual_xfer_breadcrumbs
The former two functions are reachable from IRQ handlers while
the latter two functions are not, and they call spin_lock()
which do not disable interrupt. Being preempted by an interrupt
acquiring the same lock may lead to deadlock.
Other functions acquire irq_lock by spin_lock_irq/irqsave().
This patch switches spin_lock() to spin_lock_irq in the two
process-context functions.
The issue is identified by a static analyzer based on Coccinelle.
Signed-off-by: Wang Xiayang <xywang.sjtu@xxxxxxxxxxx>
---
drivers/gpu/drm/i915/gt/intel_breadcrumbs.c | 4 ++--
drivers/gpu/drm/i915/gt/intel_lrc.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
index c092bdf5f0bf..e0b46450c2f5 100644
--- a/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
+++ b/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c
@@ -301,7 +301,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
struct intel_context *ce = rq->hw_context;
struct list_head *pos;
- spin_lock(&b->irq_lock);
+ spin_lock_irq(&b->irq_lock);
GEM_BUG_ON(test_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags));
__intel_breadcrumbs_arm_irq(b);
@@ -333,7 +333,7 @@ bool i915_request_enable_breadcrumb(struct i915_request *rq)
GEM_BUG_ON(!check_signal_order(ce, rq));
set_bit(I915_FENCE_FLAG_SIGNAL, &rq->fence.flags);
- spin_unlock(&b->irq_lock);
+ spin_unlock_irq(&b->irq_lock);
}
return !__request_completed(rq);
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 82b7ace62d97..42367aeefcce 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -806,13 +806,13 @@ static void virtual_xfer_breadcrumbs(struct virtual_engine *ve,
/* All unattached (rq->engine == old) must already be completed */
- spin_lock(&old->breadcrumbs.irq_lock);
+ spin_lock_irq(&old->breadcrumbs.irq_lock);
if (!list_empty(&ve->context.signal_link)) {
list_move_tail(&ve->context.signal_link,
&engine->breadcrumbs.signalers);
intel_engine_queue_breadcrumbs(engine);
}
- spin_unlock(&old->breadcrumbs.irq_lock);
+ spin_unlock_irq(&old->breadcrumbs.irq_lock);
}
static void execlists_dequeue(struct intel_engine_cs *engine)
--
2.11.0
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