| Message ID | 20230823182635.2618118-1-Frank.Li@nxp.com (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3f4b82167a3b1f4ddb33d890f758a042ef4ceef1 |
| Headers | show |
| Series | [1/1] dmaengine: fsl-edma: fix edma4 channel enable failure on second attempt | expand |
> -----Original Message----- > From: Frank Li <frank.li@nxp.com> > Sent: Wednesday, August 23, 2023 1:27 PM > To: vkoul@kernel.org > Cc: devicetree@vger.kernel.org; dmaengine@vger.kernel.org; Frank Li > <frank.li@nxp.com>; imx@lists.linux.dev; Joy Zou <joy.zou@nxp.com>; > krzysztof.kozlowski+dt@linaro.org; linux-kernel@vger.kernel.org; Peng Fan > <peng.fan@nxp.com>; robh+dt@kernel.org; Shenwei Wang > <shenwei.wang@nxp.com> > Subject: [PATCH 1/1] dmaengine: fsl-edma: fix edma4 channel enable failure > on second attempt > > When attempting to start DMA for the second time using > fsl_edma3_enable_request(), channel never start. > > CHn_MUX must have a unique value when selecting a peripheral slot in the > channel mux configuration. The only value that may overlap is source 0. > If there is an attempt to write a mux configuration value that is already > consumed by another channel, a mux configuration of 0 (SRC = 0) will be > written. > > Check CHn_MUX before writing in fsl_edma3_enable_request(). > > Fixes: 72f5801a4e2b ("dmaengine: fsl-edma: integrate v3 support") > Signed-off-by: Frank Li <Frank.Li@nxp.com> > --- @vinod: ping > drivers/dma/fsl-edma-common.c | 10 ++++++++-- > 1 file changed, 8 insertions(+), 2 deletions(-) > > diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma- > common.c > index a0f5741abcc4..edb92fa93315 100644 > --- a/drivers/dma/fsl-edma-common.c > +++ b/drivers/dma/fsl-edma-common.c > @@ -92,8 +92,14 @@ static void fsl_edma3_enable_request(struct > fsl_edma_chan *fsl_chan) > > edma_writel_chreg(fsl_chan, val, ch_sbr); > > - if (flags & FSL_EDMA_DRV_HAS_CHMUX) > - edma_writel_chreg(fsl_chan, fsl_chan->srcid, ch_mux); > + if (flags & FSL_EDMA_DRV_HAS_CHMUX) { > + /* > + * ch_mux: With the exception of 0, attempts to write a value > + * already in use will be forced to 0. > + */ > + if (!edma_readl_chreg(fsl_chan, ch_mux)) > + edma_writel_chreg(fsl_chan, fsl_chan->srcid, > ch_mux); > + } > > val = edma_readl_chreg(fsl_chan, ch_csr); > val |= EDMA_V3_CH_CSR_ERQ; > -- > 2.34.1
On Wed, 23 Aug 2023 14:26:35 -0400, Frank Li wrote: > When attempting to start DMA for the second time using > fsl_edma3_enable_request(), channel never start. > > CHn_MUX must have a unique value when selecting a peripheral slot in the > channel mux configuration. The only value that may overlap is source 0. > If there is an attempt to write a mux configuration value that is already > consumed by another channel, a mux configuration of 0 (SRC = 0) will be > written. > > [...] Applied, thanks! [1/1] dmaengine: fsl-edma: fix edma4 channel enable failure on second attempt commit: 3f4b82167a3b1f4ddb33d890f758a042ef4ceef1 Best regards,
diff --git a/drivers/dma/fsl-edma-common.c b/drivers/dma/fsl-edma-common.c index a0f5741abcc4..edb92fa93315 100644 --- a/drivers/dma/fsl-edma-common.c +++ b/drivers/dma/fsl-edma-common.c @@ -92,8 +92,14 @@ static void fsl_edma3_enable_request(struct fsl_edma_chan *fsl_chan) edma_writel_chreg(fsl_chan, val, ch_sbr); - if (flags & FSL_EDMA_DRV_HAS_CHMUX) - edma_writel_chreg(fsl_chan, fsl_chan->srcid, ch_mux); + if (flags & FSL_EDMA_DRV_HAS_CHMUX) { + /* + * ch_mux: With the exception of 0, attempts to write a value + * already in use will be forced to 0. + */ + if (!edma_readl_chreg(fsl_chan, ch_mux)) + edma_writel_chreg(fsl_chan, fsl_chan->srcid, ch_mux); + } val = edma_readl_chreg(fsl_chan, ch_csr); val |= EDMA_V3_CH_CSR_ERQ;
When attempting to start DMA for the second time using fsl_edma3_enable_request(), channel never start. CHn_MUX must have a unique value when selecting a peripheral slot in the channel mux configuration. The only value that may overlap is source 0. If there is an attempt to write a mux configuration value that is already consumed by another channel, a mux configuration of 0 (SRC = 0) will be written. Check CHn_MUX before writing in fsl_edma3_enable_request(). Fixes: 72f5801a4e2b ("dmaengine: fsl-edma: integrate v3 support") Signed-off-by: Frank Li <Frank.Li@nxp.com> --- drivers/dma/fsl-edma-common.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)