Hi, With the help of a static bug finder (EBA - https://github.com/models-team/eba) I have found a potential deadlock in drivers/dma/coh901318.c. This happens due to a recursive spin_lock_irqsave on `cohc->lock'. This bug may have been introduced by commit 84c8447c544b ("DMAENGINE: COH 901 318 fix bytesleft"). The fix seems easy, I would personally just remove the calls to spin_(un)lock_irqsave in lines 1805 and 1826. Function `coh901318_config' is only called by `coh901318_alloc_chan_resources' which already holds that lock when calling it. If someone can confirm that all the above is correct, I will be happy to submit a patch. The trace is as follows: 1. Function `coh901318_alloc_chan_resources' takes the lock first in line 2165: // see https://github.com/torvalds/linux/blob/master/drivers/dma/coh901318.c#L2165 spin_lock_irqsave(&cohc->lock, flags); 2. Immediately after it calls `coh901318_config' passing the `cohc' struct to it. 3. The first thing `coh901318_config' does is to take the same spinlock in line 1805: // see https://github.com/torvalds/linux/blob/master/drivers/dma/coh901318.c#L1805 spin_lock_irqsave(&cohc->lock, flags); Hope it helps! -- iago -- To unsubscribe from this list: send the line "unsubscribe dmaengine" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
