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authorAmelie Delaunay <amelie.delaunay@foss.st.com>2023-10-04 17:50:24 +0200
committerVinod Koul <vkoul@kernel.org>2023-10-09 11:10:58 +0530
commit67e13e89742c3b21ce177f612bf9ef32caae6047 (patch)
tree9d3a74c0d3a5e418112d496afb293073352c6689 /drivers/dma
parent2df467e908ce463cff1431ca1b00f650f7a514b4 (diff)
dmaengine: stm32-dma: fix residue in case of MDMA chaining
In case of MDMA chaining, DMA is configured in Double-Buffer Mode (DBM) with two periods, but if transfer has been prepared with _prep_slave_sg(), the transfer is not marked cyclic (=!chan->desc->cyclic). However, as DBM is activated for MDMA chaining, residue computation must take into account cyclic constraints. With only two periods in MDMA chaining, and no update due to Transfer Complete interrupt masked, n_sg is always 0. If DMA current memory address (depending on SxCR.CT and SxM0AR/SxM1AR) does not correspond, it means n_sg should be increased. Then, the residue of the current period is the one read from SxNDTR and should not be overwritten with the full period length. Fixes: 723795173ce1 ("dmaengine: stm32-dma: add support to trigger STM32 MDMA") Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231004155024.2609531-2-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/stm32-dma.c7
1 files changed, 4 insertions, 3 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c
index 7427acc82259..0b30151fb45c 100644
--- a/drivers/dma/stm32-dma.c
+++ b/drivers/dma/stm32-dma.c
@@ -1389,11 +1389,12 @@ static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
residue = stm32_dma_get_remaining_bytes(chan);
- if (chan->desc->cyclic && !stm32_dma_is_current_sg(chan)) {
+ if ((chan->desc->cyclic || chan->trig_mdma) && !stm32_dma_is_current_sg(chan)) {
n_sg++;
if (n_sg == chan->desc->num_sgs)
n_sg = 0;
- residue = sg_req->len;
+ if (!chan->trig_mdma)
+ residue = sg_req->len;
}
/*
@@ -1403,7 +1404,7 @@ static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan,
* residue = remaining bytes from NDTR + remaining
* periods/sg to be transferred
*/
- if (!chan->desc->cyclic || n_sg != 0)
+ if ((!chan->desc->cyclic && !chan->trig_mdma) || n_sg != 0)
for (i = n_sg; i < desc->num_sgs; i++)
residue += desc->sg_req[i].len;