The rx path of the 8250_dma user in the RX-timeout case: - it starts the RX transfer - if the rx-timeout interrupt occures, it dmaengine_pause() the transfer - step two is dmaengine_terminate_all() on this channel. - based on dmaengine_tx_status() it learns the number of transfered bytes. - the rx interrupt occures, it does not start the RX-transfer because according to dmaengine_tx_status() the status of the current transfer is still DMA_IN_PROGRESS because the earlier dmaengine_terminate_all() did not reset this. - on rx-timeout it invokes dmaengine_pause() again. This time, it segfaults because the channel has no descriptor yet. To make the upper case work better, this patch adds dma_cookie_complete() to complete the cookie. Also it adds is an additional check for echan->edesc in case the channel has no descriptor assigned. Cc: Joel Fernandes <joelf@xxxxxx> Cc: Vinod Koul <vinod.koul@xxxxxxxxx> Cc: Dan Williams <dan.j.williams@xxxxxxxxx> Cc: dmaengine@xxxxxxxxxxxxxxx Signed-off-by: Sebastian Andrzej Siewior <bigeasy@xxxxxxxxxxxxx> --- drivers/dma/edma.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/dma/edma.c b/drivers/dma/edma.c index d08c4de..ff05dd4 100644 --- a/drivers/dma/edma.c +++ b/drivers/dma/edma.c @@ -256,6 +256,7 @@ static int edma_terminate_all(struct edma_chan *echan) * echan->edesc is NULL and exit.) */ if (echan->edesc) { + dma_cookie_complete(&echan->edesc->vdesc.tx); echan->edesc = NULL; edma_stop(echan->ch_num); } @@ -282,7 +283,7 @@ static int edma_slave_config(struct edma_chan *echan, static int edma_dma_pause(struct edma_chan *echan) { /* Pause/Resume only allowed with cyclic mode */ - if (!echan->edesc->cyclic) + if (!echan->edesc || !echan->edesc->cyclic) return -EINVAL; edma_pause(echan->ch_num); -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html