From f0410bbf7d0fb80149e3b17d11d31f5b5197873e Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Fri, 29 May 2020 16:11:51 +0300 Subject: [PATCH] spi: dw: Return any value retrieved from the dma_transfer callback 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 Cc: Georgy Vlasov Cc: Ramil Zaripov Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Andy Shevchenko Cc: Feng Tang Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Link: https://lore.kernel.org/r/20200529131205.31838-3-Sergey.Semin@baikalelectronics.ru Signed-off-by: Mark Brown --- 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 b1710132b7b2..7ff1acaa55f8 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -288,7 +288,7 @@ 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 e6fc0bcf214d..73af58dbcd6a 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -389,11 +389,8 @@ 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); return 1; }