-
Tudor Ambarus authored
Fix the following deadlocks: 1/ atc_handle_cyclic() and atc_chain_complete() called dmaengine_desc_get_callback_invoke() while wrongly holding the atchan->lock. Clients can set the callback to dmaengine_terminate_sync() which will end up trying to get the same lock, thus a deadlock occurred. 2/ dma_run_dependencies() was called with the atchan->lock held, but the method calls device_issue_pending() which tries to get the same lock, and so a deadlock occurred. The driver must not hold the lock when invoking the callback or when running dependencies. Releasing the spinlock within a called function before calling the callback is not a nice thing to do -> called functions become non-atomic when called within an atomic region. Thus the lock is now taken in the child routines whereever is needed. Signed-off-by:
Tudor Ambarus <tudor.ambarus@microchip.com> Acked-by:
Ludovic Desroches <ludovic.desroches@microchip.com> Link: https://lore.kernel.org/r/20200123140237.125799-6-tudor.ambarus@microchip.comSigned-off-by:
Vinod Koul <vkoul@kernel.org>
078a6506