diff options
| author | Tomasz Moń | 2022-01-17 10:19:55 +0100 |
|---|---|---|
| committer | Vinod Koul | 2022-02-15 11:11:06 +0530 |
| commit | 177360e04b70b1d3937471e42201cdbb831a82da (patch) | |
| tree | a36f93feae648f04e9995e5d4abff01e5cb2053e | |
| parent | 5b215c28b923539a04587b6a3f78a449f967ae32 (diff) | |
dmaengine: imx-sdma: fix cyclic buffer race condition
Assign buffer ownership to SDMA after invoking descriptor callback to
make sure that SDMA does not write to the buffer before it is read by
the CPU.
Signed-off-by: Tomasz Moń <tomasz.mon@camlingroup.com>
Link: https://lore.kernel.org/r/20220117091955.1038937-2-tomasz.mon@camlingroup.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
| -rw-r--r-- | drivers/dma/imx-sdma.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/dma/imx-sdma.c b/drivers/dma/imx-sdma.c index 330ff41cd614..8cc5103193c3 100644 --- a/drivers/dma/imx-sdma.c +++ b/drivers/dma/imx-sdma.c @@ -847,7 +847,6 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) */ desc->chn_real_count = bd->mode.count; - bd->mode.status |= BD_DONE; bd->mode.count = desc->period_len; desc->buf_ptail = desc->buf_tail; desc->buf_tail = (desc->buf_tail + 1) % desc->num_bd; @@ -862,6 +861,9 @@ static void sdma_update_channel_loop(struct sdma_channel *sdmac) dmaengine_desc_get_callback_invoke(&desc->vd.tx, NULL); spin_lock(&sdmac->vc.lock); + /* Assign buffer ownership to SDMA */ + bd->mode.status |= BD_DONE; + if (error) sdmac->status = old_status; } |