diff options
| author | Leonid Iziumtsev <leonid.iziumtsev@gmail.com> | 2019-01-15 20:15:23 +0300 |
|---|---|---|
| committer | Vinod Koul <vkoul@kernel.org> | 2019-02-04 10:05:12 +0300 |
| commit | 341198eda723c8c1cddbb006a89ad9e362502ea2 (patch) | |
| tree | 915e69ff12f1e7566caa5d64254f09dcc15a020b /drivers/dma/imx-dma.c | |
| parent | dc3f595b6617ebc0307e0ce151e8f2f2b2489b95 (diff) | |
| download | linux-341198eda723c8c1cddbb006a89ad9e362502ea2.tar.xz | |
dmaengine: imx-dma: fix wrong callback invoke
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
Diffstat (limited to 'drivers/dma/imx-dma.c')
| -rw-r--r-- | drivers/dma/imx-dma.c | 8 |
1 files changed, 4 insertions, 4 deletions
diff --git a/drivers/dma/imx-dma.c b/drivers/dma/imx-dma.c index c2fff3f6c9ca..4a09af3cd546 100644 --- a/drivers/dma/imx-dma.c +++ b/drivers/dma/imx-dma.c @@ -618,7 +618,7 @@ 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); @@ -648,10 +648,10 @@ 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); } |