On 21-05-20 11:42:24, Pawel Laszczak wrote:
From: Pawel Laszczak pawell@cadence.com
Patch fixes the critical issue caused by deadlock which has been detected during testing NCM class.
The root cause of issue is spin_lock/spin_unlock instruction instead spin_lock_irqsave/spin_lock_irqrestore in cdnsp_thread_irq_handler function.
Pawel, would you please explain more about why the deadlock occurs with current code, and why this patch could fix it?
Peter
Cc: stable@vger.kernel.org Fixes: 3d82904559f4 ("usb: cdnsp: cdns3 Add main part of Cadence USBSSP DRD Driver") Signed-off-by: Pawel Laszczak pawell@cadence.com
drivers/usb/cdns3/cdnsp-ring.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/cdns3/cdnsp-ring.c b/drivers/usb/cdns3/cdnsp-ring.c index 5f0513c96c04..68972746e363 100644 --- a/drivers/usb/cdns3/cdnsp-ring.c +++ b/drivers/usb/cdns3/cdnsp-ring.c @@ -1517,13 +1517,14 @@ irqreturn_t cdnsp_thread_irq_handler(int irq, void *data) { struct cdnsp_device *pdev = (struct cdnsp_device *)data; union cdnsp_trb *event_ring_deq;
- unsigned long flags; int counter = 0;
- spin_lock(&pdev->lock);
- spin_lock_irqsave(&pdev->lock, flags);
if (pdev->cdnsp_state & (CDNSP_STATE_HALTED | CDNSP_STATE_DYING)) { cdnsp_died(pdev);
spin_unlock(&pdev->lock);
spin_unlock_irqrestore(&pdev->lock, flags);@@ -1539,7 +1540,7 @@ irqreturn_t cdnsp_thread_irq_handler(int irq, void *data) cdnsp_update_erst_dequeue(pdev, event_ring_deq, 1);
- spin_unlock(&pdev->lock);
- spin_unlock_irqrestore(&pdev->lock, flags);
return IRQ_HANDLED; } -- 2.25.1