From: Amelie Delaunay <amelie.delaunay@foss.st.com> To: Vinod Koul <vkoul@kernel.org>, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Alexandre Torgue <alexandre.torgue@foss.st.com>, Amelie Delaunay <amelie.delaunay@foss.st.com> Cc: <stable@vger.kernel.org>, <dmaengine@vger.kernel.org>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH 2/2] dmaengine: stm32-dma: fix residue in case of MDMA chaining Date: Wed, 4 Oct 2023 17:50:24 +0200 [thread overview] Message-ID: <20231004155024.2609531-2-amelie.delaunay@foss.st.com> (raw) In-Reply-To: <20231004155024.2609531-1-amelie.delaunay@foss.st.com> 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 --- drivers/dma/stm32-dma.c | 7 ++++--- 1 file 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; -- 2.25.1
WARNING: multiple messages have this Message-ID (diff)
From: Amelie Delaunay <amelie.delaunay@foss.st.com> To: Vinod Koul <vkoul@kernel.org>, Maxime Coquelin <mcoquelin.stm32@gmail.com>, Alexandre Torgue <alexandre.torgue@foss.st.com>, Amelie Delaunay <amelie.delaunay@foss.st.com> Cc: <stable@vger.kernel.org>, <dmaengine@vger.kernel.org>, <linux-stm32@st-md-mailman.stormreply.com>, <linux-arm-kernel@lists.infradead.org>, <linux-kernel@vger.kernel.org> Subject: [PATCH 2/2] dmaengine: stm32-dma: fix residue in case of MDMA chaining Date: Wed, 4 Oct 2023 17:50:24 +0200 [thread overview] Message-ID: <20231004155024.2609531-2-amelie.delaunay@foss.st.com> (raw) In-Reply-To: <20231004155024.2609531-1-amelie.delaunay@foss.st.com> 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 --- drivers/dma/stm32-dma.c | 7 ++++--- 1 file 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; -- 2.25.1 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2023-10-04 15:50 UTC|newest] Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-10-04 15:50 [PATCH 1/2] dmaengine: stm32-dma: fix stm32_dma_prep_slave_sg in case of MDMA chaining Amelie Delaunay 2023-10-04 15:50 ` Amelie Delaunay 2023-10-04 15:50 ` Amelie Delaunay [this message] 2023-10-04 15:50 ` [PATCH 2/2] dmaengine: stm32-dma: fix residue " Amelie Delaunay 2023-10-09 6:12 ` [PATCH 1/2] dmaengine: stm32-dma: fix stm32_dma_prep_slave_sg " Vinod Koul 2023-10-09 6:12 ` Vinod Koul
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