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authorAmelie Delaunay <amelie.delaunay@foss.st.com>2023-10-04 19:35:30 +0300
committerVinod Koul <vkoul@kernel.org>2023-10-09 08:40:30 +0300
commit584970421725b7805db84714b857851fdf7203a9 (patch)
tree5ccfcd4336a1dc98cc93ad75e8c9a1e8419375b0 /drivers/dma
parenta4b306eb83579c07b63dc65cd5bae53b7b4019d0 (diff)
downloadlinux-584970421725b7805db84714b857851fdf7203a9.tar.xz
dmaengine: stm32-mdma: set in_flight_bytes in case CRQA flag is set
CRQA flag is set by hardware when the channel request become active and the channel is enabled. It is cleared by hardware, when the channel request is completed. So when it is set, it means MDMA is transferring bytes. This information is useful in case of STM32 DMA and MDMA chaining, especially when the user pauses DMA before stopping it, to trig one last MDMA transfer to get the latest bytes of the SRAM buffer to the destination buffer. STM32 DCMI driver can then use this to know if the last MDMA transfer in case of chaining is done. Fixes: 696874322771 ("dmaengine: stm32-mdma: add support to be triggered by STM32 DMA") Signed-off-by: Amelie Delaunay <amelie.delaunay@foss.st.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20231004163531.2864160-3-amelie.delaunay@foss.st.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
Diffstat (limited to 'drivers/dma')
-rw-r--r--drivers/dma/stm32-mdma.c14
1 files changed, 9 insertions, 5 deletions
diff --git a/drivers/dma/stm32-mdma.c b/drivers/dma/stm32-mdma.c
index da73e13b8c9d..bae08b3f55c7 100644
--- a/drivers/dma/stm32-mdma.c
+++ b/drivers/dma/stm32-mdma.c
@@ -1318,7 +1318,8 @@ static int stm32_mdma_slave_config(struct dma_chan *c,
static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
struct stm32_mdma_desc *desc,
- u32 curr_hwdesc)
+ u32 curr_hwdesc,
+ struct dma_tx_state *state)
{
struct stm32_mdma_device *dmadev = stm32_mdma_get_dev(chan);
struct stm32_mdma_hwdesc *hwdesc;
@@ -1342,6 +1343,10 @@ static size_t stm32_mdma_desc_residue(struct stm32_mdma_chan *chan,
cbndtr = stm32_mdma_read(dmadev, STM32_MDMA_CBNDTR(chan->id));
residue += cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
+ state->in_flight_bytes = 0;
+ if (chan->chan_config.m2m_hw && (cisr & STM32_MDMA_CISR_CRQA))
+ state->in_flight_bytes = cbndtr & STM32_MDMA_CBNDTR_BNDT_MASK;
+
if (!chan->mem_burst)
return residue;
@@ -1371,11 +1376,10 @@ static enum dma_status stm32_mdma_tx_status(struct dma_chan *c,
vdesc = vchan_find_desc(&chan->vchan, cookie);
if (chan->desc && cookie == chan->desc->vdesc.tx.cookie)
- residue = stm32_mdma_desc_residue(chan, chan->desc,
- chan->curr_hwdesc);
+ residue = stm32_mdma_desc_residue(chan, chan->desc, chan->curr_hwdesc, state);
else if (vdesc)
- residue = stm32_mdma_desc_residue(chan,
- to_stm32_mdma_desc(vdesc), 0);
+ residue = stm32_mdma_desc_residue(chan, to_stm32_mdma_desc(vdesc), 0, state);
+
dma_set_residue(state, residue);
spin_unlock_irqrestore(&chan->vchan.lock, flags);