On 10.01.2025 15:08, Krzysztof Karas wrote:
spin_unlock() function enables irqs regardless of their state
before spin_lock() was called. This might result in an interrupt
while holding a lock further down in the execution, as seen in
GitLab issue #13399.
Try to remedy the problem by saving irq state before spin lock
acquisition.
Signed-off-by: Krzysztof Karas <krzysztof.karas@xxxxxxxxx>
---
This issue is hit rarely on CI and I was not able to reproduce
it locally. There might be more places where we should save and
restore irq state, so I am not adding "Closes" label for the
issue yet.
drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 12f1ba7ca9c1..e9102f7246f5 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -4338,10 +4338,11 @@ static void guc_bump_inflight_request_prio(struct i915_request *rq,
static void guc_retire_inflight_request_prio(struct i915_request *rq)
{
struct intel_context *ce = request_to_scheduling_context(rq);
+ unsigned long flags;
- spin_lock(&ce->guc_state.lock);
+ spin_lock_irqsave(&ce->guc_state.lock, flags);
guc_prio_fini(rq, ce);
- spin_unlock(&ce->guc_state.lock);
+ spin_unlock_irqrestore(&ce->guc_state.lock, flags);
}
static void sanitize_hwsp(struct intel_engine_cs *engine)
The guc_retire_inflight_request_prio is called in intel_breadcrumbs.c
signal_irq_work().
There is a similar situation
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/drivers/gpu/drm/i915/gt/intel_breadcrumbs.c?h=v6.13-rc7#n255
There is also spin_(un)lock while potentially IRQs are disabled.
Should it also be addressed?
Regards,
Maciej
