[PATCH AUTOSEL 4.14 146/150] spi: omap2-mcspi: Fix DMA and FIFO event trigger size mismatch

Sasha Levin
2019-11-16T16:05:56Z

From: Vignesh R <vigneshr@ti.com>

[ Upstream commit baf8b9f8d260c55a86405f70a384c29cda888476 ]

Commit b682cffa3ac6 ("spi: omap2-mcspi: Set FIFO DMA trigger level to word length")
broke SPI transfers where bits_per_word != 8. This is because of
mimsatch between McSPI FIFO level event trigger size (SPI word length) and
DMA request size(word length * maxburst). This leads to data
corruption, lockup and errors like:

spi1.0: EOW timed out

Fix this by setting DMA maxburst size to 1 so that
McSPI FIFO level event trigger size matches DMA request size.

Fixes: b682cffa3ac6 ("spi: omap2-mcspi: Set FIFO DMA trigger level to word length")
Cc: stable@vger.kernel.org
Reported-by: David Lechner <david@lechnology.com>
Tested-by: David Lechner <david@lechnology.com>
Signed-off-by: Vignesh R <vigneshr@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/spi/spi-omap2-mcspi.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/spi/spi-omap2-mcspi.c b/drivers/spi/spi-omap2-mcspi.c
index 517d0ade586bd..1db4d3c1d2bfa 100644
--- a/drivers/spi/spi-omap2-mcspi.c
+++ b/drivers/spi/spi-omap2-mcspi.c
@@ -625,8 +625,8 @@ omap2_mcspi_txrx_dma(struct spi_device *spi, struct spi_transfer *xfer)
cfg.dst_addr = cs->phys + OMAP2_MCSPI_TX0;
cfg.src_addr_width = width;
cfg.dst_addr_width = width;
- cfg.src_maxburst = es;
- cfg.dst_maxburst = es;
+ cfg.src_maxburst = 1;
+ cfg.dst_maxburst = 1;

rx = xfer->rx_buf;
tx = xfer->tx_buf;
--
2.20.1