accel/habanalabs: fix bug in decoder wait for cs completion

The decoder interrupts are handled in the interrupt context
same as all user interrupts.
In such case, the wait list should be protected by
spin_lock_irqsave in order to avoid deadlock that might happen
with the user submission flow.

Signed-off-by: farah kassabri <fkassabri@habana.ai>
Reviewed-by: Oded Gabbay <ogabbay@kernel.org>
Signed-off-by: Oded Gabbay <ogabbay@kernel.org>

diff --git a/drivers/accel/habanalabs/common/command_submission.c b/drivers/accel/habanalabs/common/command_submission.c
index 4f7b70d9754c314a7945adecae6833af89a5ef77..3aa6eeef443b4174466e8e397e30795da293091a 100644 (file)
--- a/drivers/accel/habanalabs/common/command_submission.c
+++ b/drivers/accel/habanalabs/common/command_submission.c
@@ -3526,7 +3526,7 @@ static int _hl_interrupt_wait_ioctl_user_addr(struct hl_device *hdev, struct hl_
                                u64 *timestamp)
 {
        struct hl_user_pending_interrupt *pend;
-       unsigned long timeout;
+       unsigned long timeout, flags;
        u64 completion_value;
        long completion_rc;
        int rc = 0;
@@ -3546,9 +3546,9 @@ static int _hl_interrupt_wait_ioctl_user_addr(struct hl_device *hdev, struct hl_
        /* Add pending user interrupt to relevant list for the interrupt
         * handler to monitor
         */
-       spin_lock(&interrupt->wait_list_lock);
+       spin_lock_irqsave(&interrupt->wait_list_lock, flags);
        list_add_tail(&pend->list_node, &interrupt->wait_list_head);
-       spin_unlock(&interrupt->wait_list_lock);
+       spin_unlock_irqrestore(&interrupt->wait_list_lock, flags);
 
        /* We check for completion value as interrupt could have been received
         * before we added the node to the wait list
@@ -3579,14 +3579,14 @@ wait_again:
         * If comparison fails, keep waiting until timeout expires
         */
        if (completion_rc > 0) {
-               spin_lock(&interrupt->wait_list_lock);
+               spin_lock_irqsave(&interrupt->wait_list_lock, flags);
                /* reinit_completion must be called before we check for user
                 * completion value, otherwise, if interrupt is received after
                 * the comparison and before the next wait_for_completion,
                 * we will reach timeout and fail
                 */
                reinit_completion(&pend->fence.completion);
-               spin_unlock(&interrupt->wait_list_lock);
+               spin_unlock_irqrestore(&interrupt->wait_list_lock, flags);
 
                if (copy_from_user(&completion_value, u64_to_user_ptr(user_address), 8)) {
                        dev_err(hdev->dev, "Failed to copy completion value from user\n");
@@ -3623,9 +3623,9 @@ wait_again:
        }
 
 remove_pending_user_interrupt:
-       spin_lock(&interrupt->wait_list_lock);
+       spin_lock_irqsave(&interrupt->wait_list_lock, flags);
        list_del(&pend->list_node);
-       spin_unlock(&interrupt->wait_list_lock);
+       spin_unlock_irqrestore(&interrupt->wait_list_lock, flags);
 
        *timestamp = ktime_to_ns(pend->fence.timestamp);