| Message ID | 20200828074726.24546-1-vigneshr@ti.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | spi: spi-cadence-quadspi: Fix mapping of buffers for DMA reads | expand |
On 28.08.20 09:47, Vignesh Raghavendra wrote: > Buffers need to mapped to DMA channel's device pointer instead of SPI > controller's device pointer as its system DMA that actually does data > transfer. > Data inconsistencies have been reported when reading from flash > without this fix. > > Fixes: 31fb632b5d43c ("spi: Move cadence-quadspi driver to drivers/spi/") This looks wrong, ... > Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> > --- > > This issue was present in the original driver under SPI NOR framework as well. > But only got exposed as driver started handling probe deferral for DMA channel > request and thus uses DMA almost always unlike before. ...you rather want 935da5e5100f57d843cac4781b21f1c235059aa0 then. Other than that: Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Thanks! Jan > > drivers/spi/spi-cadence-quadspi.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c > index 508b219eabf8..c6795c684b16 100644 > --- a/drivers/spi/spi-cadence-quadspi.c > +++ b/drivers/spi/spi-cadence-quadspi.c > @@ -907,14 +907,16 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, > struct dma_async_tx_descriptor *tx; > dma_cookie_t cookie; > dma_addr_t dma_dst; > + struct device *ddev; > > if (!cqspi->rx_chan || !virt_addr_valid(buf)) { > memcpy_fromio(buf, cqspi->ahb_base + from, len); > return 0; > } > > - dma_dst = dma_map_single(dev, buf, len, DMA_FROM_DEVICE); > - if (dma_mapping_error(dev, dma_dst)) { > + ddev = cqspi->rx_chan->device->dev; > + dma_dst = dma_map_single(ddev, buf, len, DMA_FROM_DEVICE); > + if (dma_mapping_error(ddev, dma_dst)) { > dev_err(dev, "dma mapping failed\n"); > return -ENOMEM; > } > @@ -948,7 +950,7 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, > } > > err_unmap: > - dma_unmap_single(dev, dma_dst, len, DMA_FROM_DEVICE); > + dma_unmap_single(ddev, dma_dst, len, DMA_FROM_DEVICE); > > return ret; > } >
On 8/28/20 1:56 PM, Jan Kiszka wrote: > On 28.08.20 09:47, Vignesh Raghavendra wrote: >> Buffers need to mapped to DMA channel's device pointer instead of SPI >> controller's device pointer as its system DMA that actually does data >> transfer. >> Data inconsistencies have been reported when reading from flash >> without this fix. >> >> Fixes: 31fb632b5d43c ("spi: Move cadence-quadspi driver to drivers/spi/") > > This looks wrong, ... > >> Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> >> --- >> >> This issue was present in the original driver under SPI NOR framework as well. >> But only got exposed as driver started handling probe deferral for DMA channel >> request and thus uses DMA almost always unlike before. > > ...you rather want 935da5e5100f57d843cac4781b21f1c235059aa0 then. > Actually, the offending code is actually from commit ffa639e069fb ("mtd: spi-nor: cadence-quadspi: Add DMA support for direct mode reads) which adds dma_{un}map_single() calls. Will send v2 with Fixes tag updated to point to above commit > Other than that: > > Tested-by: Jan Kiszka <jan.kiszka@siemens.com> Thanks! Regards Vignesh > > Thanks! > Jan > >> >> drivers/spi/spi-cadence-quadspi.c | 8 +++++--- >> 1 file changed, 5 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c >> index 508b219eabf8..c6795c684b16 100644 >> --- a/drivers/spi/spi-cadence-quadspi.c >> +++ b/drivers/spi/spi-cadence-quadspi.c >> @@ -907,14 +907,16 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, >> struct dma_async_tx_descriptor *tx; >> dma_cookie_t cookie; >> dma_addr_t dma_dst; >> + struct device *ddev; >> >> if (!cqspi->rx_chan || !virt_addr_valid(buf)) { >> memcpy_fromio(buf, cqspi->ahb_base + from, len); >> return 0; >> } >> >> - dma_dst = dma_map_single(dev, buf, len, DMA_FROM_DEVICE); >> - if (dma_mapping_error(dev, dma_dst)) { >> + ddev = cqspi->rx_chan->device->dev; >> + dma_dst = dma_map_single(ddev, buf, len, DMA_FROM_DEVICE); >> + if (dma_mapping_error(ddev, dma_dst)) { >> dev_err(dev, "dma mapping failed\n"); >> return -ENOMEM; >> } >> @@ -948,7 +950,7 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, >> } >> >> err_unmap: >> - dma_unmap_single(dev, dma_dst, len, DMA_FROM_DEVICE); >> + dma_unmap_single(ddev, dma_dst, len, DMA_FROM_DEVICE); >> >> return ret; >> } >> >
diff --git a/drivers/spi/spi-cadence-quadspi.c b/drivers/spi/spi-cadence-quadspi.c index 508b219eabf8..c6795c684b16 100644 --- a/drivers/spi/spi-cadence-quadspi.c +++ b/drivers/spi/spi-cadence-quadspi.c @@ -907,14 +907,16 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, struct dma_async_tx_descriptor *tx; dma_cookie_t cookie; dma_addr_t dma_dst; + struct device *ddev; if (!cqspi->rx_chan || !virt_addr_valid(buf)) { memcpy_fromio(buf, cqspi->ahb_base + from, len); return 0; } - dma_dst = dma_map_single(dev, buf, len, DMA_FROM_DEVICE); - if (dma_mapping_error(dev, dma_dst)) { + ddev = cqspi->rx_chan->device->dev; + dma_dst = dma_map_single(ddev, buf, len, DMA_FROM_DEVICE); + if (dma_mapping_error(ddev, dma_dst)) { dev_err(dev, "dma mapping failed\n"); return -ENOMEM; } @@ -948,7 +950,7 @@ static int cqspi_direct_read_execute(struct cqspi_flash_pdata *f_pdata, } err_unmap: - dma_unmap_single(dev, dma_dst, len, DMA_FROM_DEVICE); + dma_unmap_single(ddev, dma_dst, len, DMA_FROM_DEVICE); return ret; }
Buffers need to mapped to DMA channel's device pointer instead of SPI controller's device pointer as its system DMA that actually does data transfer. Data inconsistencies have been reported when reading from flash without this fix. Fixes: 31fb632b5d43c ("spi: Move cadence-quadspi driver to drivers/spi/") Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com> --- This issue was present in the original driver under SPI NOR framework as well. But only got exposed as driver started handling probe deferral for DMA channel request and thus uses DMA almost always unlike before. drivers/spi/spi-cadence-quadspi.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-)