From: Vincent Whitchurch vincent.whitchurch@axis.com
[ Upstream commit 1224e29572f655facfcd850cf0f0a4784f36a903 ]
The COUNT_VALUE in the PACKET_CNT register is 16-bit so the maximum value is 65535. Asking the driver to transfer a larger size currently leads to the DMA transfer timing out. Implement ->max_transfer_size() and have the core split the transfer as needed.
Fixes: 230d42d422e7 ("spi: Add s3c64xx SPI Controller driver") Signed-off-by: Vincent Whitchurch vincent.whitchurch@axis.com Link: https://lore.kernel.org/r/20220927112117.77599-5-vincent.whitchurch@axis.com Signed-off-by: Mark Brown broonie@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/spi/spi-s3c64xx.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index 651c35dd9124..71d324ec9a70 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -84,6 +84,7 @@ #define S3C64XX_SPI_ST_TX_FIFORDY (1<<0)
#define S3C64XX_SPI_PACKET_CNT_EN (1<<16) +#define S3C64XX_SPI_PACKET_CNT_MASK GENMASK(15, 0)
#define S3C64XX_SPI_PND_TX_UNDERRUN_CLR (1<<4) #define S3C64XX_SPI_PND_TX_OVERRUN_CLR (1<<3) @@ -711,6 +712,13 @@ static int s3c64xx_spi_prepare_message(struct spi_master *master, return 0; }
+static size_t s3c64xx_spi_max_transfer_size(struct spi_device *spi) +{ + struct spi_controller *ctlr = spi->controller; + + return ctlr->can_dma ? S3C64XX_SPI_PACKET_CNT_MASK : SIZE_MAX; +} + static int s3c64xx_spi_transfer_one(struct spi_master *master, struct spi_device *spi, struct spi_transfer *xfer) @@ -1152,6 +1160,7 @@ static int s3c64xx_spi_probe(struct platform_device *pdev) master->unprepare_transfer_hardware = s3c64xx_spi_unprepare_transfer; master->prepare_message = s3c64xx_spi_prepare_message; master->transfer_one = s3c64xx_spi_transfer_one; + master->max_transfer_size = s3c64xx_spi_max_transfer_size; master->num_chipselect = sci->num_cs; master->use_gpio_descriptors = true; master->dma_alignment = 8;