From a3d3eab627bbbb0cb175910cf8d0f7022628a642 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 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 --- 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 9fcbe040cb2f..f726d8670428 100644 --- a/drivers/spi/spi-s3c64xx.c +++ b/drivers/spi/spi-s3c64xx.c @@ -430,7 +430,7 @@ 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; } @@ -826,10 +826,9 @@ 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;