From 8ded6e5e0b04381816ad560779c34ff14849ac64 Mon Sep 17 00:00:00 2001 From: Serge Semin Date: Tue, 22 Sep 2020 10:21:35 +0800 Subject: [PATCH] spi: dw: Return any value retrieved from the dma_transfer callback stable inclusion from linux-4.19.129 commit 6d15fe48f50af2027c3292827c65277285acb9dc -------------------------------- [ 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 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 Signed-off-by: Sasha Levin Signed-off-by: Yang Yingliang --- 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 e1b34ef9a31c..10f328558d55 100644 --- a/drivers/spi/spi-dw-mid.c +++ b/drivers/spi/spi-dw-mid.c @@ -274,7 +274,7 @@ 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 db56595409bf..66765a15cd93 100644 --- a/drivers/spi/spi-dw.c +++ b/drivers/spi/spi-dw.c @@ -383,11 +383,8 @@ 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); -- GitLab