From 17c82c67c139a01a226a1a875fd62b9c0a06aaa3 Mon Sep 17 00:00:00 2001 From: Jaewon Kim Date: Fri, 29 Mar 2024 17:58:40 +0900 Subject: [PATCH] spi: s3c64xx: Use DMA mode from fifo size [ Upstream commit a3d3eab627bbbb0cb175910cf8d0f7022628a642 ] If the SPI data size is smaller than FIFO, it operates in PIO mode, and if it is larger than FIFO size, it oerates in DMA mode. If the SPI data size is equal to fifo, it operates in PIO mode and it is separated to 2 transfers. To prevent it, it must operate in DMA mode from the case where the data size and the fifo size are the same. Fixes: 1ee806718d5e ("spi: s3c64xx: support interrupt based pio mode") Signed-off-by: Jaewon Kim Reviewed-by: Sam Protsenko Link: https://lore.kernel.org/r/20240329085840.65856-1-jaewon02.kim@samsung.com Signed-off-by: Mark Brown Signed-off-by: Sasha Levin --- drivers/spi/spi-s3c64xx.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c index e059fb9db1da..652eadbefe24 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -424,7 +424,7 @@ static bool s3c64xx_spi_can_dma(struct spi_controller *host, struct s3c64xx_spi_driver_data *sdd = spi_controller_get_devdata(host); if (sdd->rx_dma.ch && sdd->tx_dma.ch) - return xfer->len > sdd->fifo_depth; + return xfer->len >= sdd->fifo_depth; return false; } @@ -783,10 +783,9 @@ static int s3c64xx_spi_transfer_one(struct spi_controller *host, return status; } - if (!is_polling(sdd) && (xfer->len > fifo_len) && + if (!is_polling(sdd) && xfer->len >= fifo_len && sdd->rx_dma.ch && sdd->tx_dma.ch) { use_dma = 1; - } else if (xfer->len >= fifo_len) { tx_buf = xfer->tx_buf; rx_buf = xfer->rx_buf;