From b191f1953846029cff59e07eb73502dccc87010d Mon Sep 17 00:00:00 2001 From: Leonid Iziumtsev Date: Tue, 15 Jan 2019 17:15:23 +0000 Subject: dmaengine: imx-dma: fix wrong callback invoke commit 341198eda723c8c1cddbb006a89ad9e362502ea2 upstream. Once the "ld_queue" list is not empty, next descriptor will migrate into "ld_active" list. The "desc" variable will be overwritten during that transition. And later the dmaengine_desc_get_callback_invoke() will use it as an argument. As result we invoke wrong callback. That behaviour was in place since: commit fcaaba6c7136 ("dmaengine: imx-dma: fix callback path in tasklet"). But after commit 4cd13c21b207 ("softirq: Let ksoftirqd do its job") things got worse, since possible delay between tasklet_schedule() from DMA irq handler and actual tasklet function execution got bigger. And that gave more time for new DMA request to be submitted and to be put into "ld_queue" list. It has been noticed that DMA issue is causing problems for "mxc-mmc" driver. While stressing the system with heavy network traffic and writing/reading to/from sd card simultaneously the timeout may happen: 10013000.sdhci: mxcmci_watchdog: read time out (status = 0x30004900) That often lead to file system corruption. Signed-off-by: Leonid Iziumtsev Signed-off-by: Vinod Koul Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/dma/imx-dma.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'drivers/dma/imx-dma.c') diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c index 48d85f8b95fe..dfa337ae06fc 100644 --- a/drivers/dma/imx-dma.c +++ b/drivers/dma/imx-dma.c @@ -619,7 +619,7 @@ static void imxdma_tasklet(unsigned long data) { struct imxdma_channel *imxdmac = (void *)data; struct imxdma_engine *imxdma = imxdmac->imxdma; - struct imxdma_desc *desc; + struct imxdma_desc *desc, *next_desc; unsigned long flags; spin_lock_irqsave(&imxdma->lock, flags); @@ -649,10 +649,10 @@ static void imxdma_tasklet(unsigned long data) list_move_tail(imxdmac->ld_active.next, &imxdmac->ld_free); if (!list_empty(&imxdmac->ld_queue)) { - desc = list_first_entry(&imxdmac->ld_queue, struct imxdma_desc, - node); + next_desc = list_first_entry(&imxdmac->ld_queue, + struct imxdma_desc, node); list_move_tail(imxdmac->ld_queue.next, &imxdmac->ld_active); - if (imxdma_xfer_desc(desc) < 0) + if (imxdma_xfer_desc(next_desc) < 0) dev_warn(imxdma->dev, "%s: channel: %d couldn't xfer desc\n", __func__, imxdmac->channel); } -- cgit v1.2.3