diff options
authorLeonid Iziumtsev <leonid.iziumtsev@gmail.com>2019-01-15 17:15:23 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-12 19:45:01 +0100
commitd9f82def817a91b5c7f66844fc94397056c61792 (patch)
parent3c8307940e46e772e39694178776c73ec9be8f77 (diff)
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 <leonid.iziumtsev@gmail.com> Signed-off-by: Vinod Koul <vkoul@kernel.org> Cc: stable@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c
index ab0fb804fb1e..1cfa1d9bc971 100644
--- a/drivers/dma/imx-dma.c
+++ b/drivers/dma/imx-dma.c
@@ -623,7 +623,7 @@ 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);
@@ -653,10 +653,10 @@ 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);