[PATCH 8/8] accel/ivpu: Fix deadlock in context_xa

Jacek Lawrynowicz jacek.lawrynowicz at linux.intel.com
Tue Apr 2 10:49:29 UTC 2024


ivpu_device->context_xa is locked both in kernel thread and IRQ context.
It requires XA_FLAGS_LOCK_IRQ flag to be passed during initialization
otherwise the lock could be acquired from a thread and interrupted by
an IRQ that locks it for the second time causing the deadlock.

This deadlock was reported by lockdep and observed in internal tests.

Fixes: 35b137630f08 ("accel/ivpu: Introduce a new DRM driver for Intel VPU")
Cc: <stable at vger.kernel.org> # v6.3+
Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz at linux.intel.com>
---
 drivers/accel/ivpu/ivpu_drv.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/accel/ivpu/ivpu_drv.c b/drivers/accel/ivpu/ivpu_drv.c
index 77283daaedd1..51d3f1a55d02 100644
--- a/drivers/accel/ivpu/ivpu_drv.c
+++ b/drivers/accel/ivpu/ivpu_drv.c
@@ -517,7 +517,7 @@ static int ivpu_dev_init(struct ivpu_device *vdev)
 	vdev->context_xa_limit.min = IVPU_USER_CONTEXT_MIN_SSID;
 	vdev->context_xa_limit.max = IVPU_USER_CONTEXT_MAX_SSID;
 	atomic64_set(&vdev->unique_id_counter, 0);
-	xa_init_flags(&vdev->context_xa, XA_FLAGS_ALLOC);
+	xa_init_flags(&vdev->context_xa, XA_FLAGS_ALLOC | XA_FLAGS_LOCK_IRQ);
 	xa_init_flags(&vdev->submitted_jobs_xa, XA_FLAGS_ALLOC1);
 	xa_init_flags(&vdev->db_xa, XA_FLAGS_ALLOC1);
 	lockdep_set_class(&vdev->submitted_jobs_xa.xa_lock, &submitted_jobs_xa_lock_class_key);
-- 
2.43.2



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