From: Serge Semin Sergey.Semin@baikalelectronics.ru
[ Upstream commit f0410bbf7d0fb80149e3b17d11d31f5b5197873e ]
DW APB SSI DMA-part of the driver may need to perform the requested SPI-transfer synchronously. In that case the dma_transfer() callback will return 0 as a marker of the SPI transfer being finished so the SPI core doesn't need to wait and may proceed with the SPI message trasnfers pumping procedure. This will be needed to fix the problem when DMA transactions are finished, but there is still data left in the SPI Tx/Rx FIFOs being sent/received. But for now make dma_transfer to return 1 as the normal dw_spi_transfer_one() method.
Signed-off-by: Serge Semin Sergey.Semin@baikalelectronics.ru Cc: Georgy Vlasov Georgy.Vlasov@baikalelectronics.ru Cc: Ramil Zaripov Ramil.Zaripov@baikalelectronics.ru Cc: Alexey Malahov Alexey.Malahov@baikalelectronics.ru Cc: Thomas Bogendoerfer tsbogend@alpha.franken.de Cc: Arnd Bergmann arnd@arndb.de Cc: Andy Shevchenko andriy.shevchenko@linux.intel.com Cc: Feng Tang feng.tang@intel.com Cc: Rob Herring robh+dt@kernel.org Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200529131205.31838-3-Sergey.Semin@baikalelectron... Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-dw-mid.c | 2 +- drivers/spi/spi-dw.c | 7 ++----- 2 files changed, 3 insertions(+), 6 deletions(-)
diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c index b044d4071690..b07710c76fc9 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -266,7 +266,7 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer) dma_async_issue_pending(dws->txchan); }
- return 0; + return 1; }
static void mid_spi_dma_stop(struct dw_spi *dws) diff --git a/drivers/spi/spi-dw.c b/drivers/spi/spi-dw.c index 07d1c170c657..c2f96941ad04 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -381,11 +381,8 @@ static int dw_spi_transfer_one(struct spi_controller *master,
spi_enable_chip(dws, 1);
- if (dws->dma_mapped) { - ret = dws->dma_ops->dma_transfer(dws, transfer); - if (ret < 0) - return ret; - } + if (dws->dma_mapped) + return dws->dma_ops->dma_transfer(dws, transfer);
if (chip->poll_mode) return poll_transfer(dws);