[PATCH 5.10 106/112] tty: serial: samsung_tty: set dma burst_size to 1

Greg Kroah-Hartman
2022-07-19T12:25:22Z

From: Chanho Park <chanho61.park@samsung.com>

commit f7e35e4bf1e8dc2c8cbd5e0955dc1bd58558dae0 upstream.

The src_maxburst and dst_maxburst have been changed to 1 but the settings
of the UCON register aren't changed yet. They should be changed as well
according to the dmaengine slave config.

Fixes: aa2f80e752c7 ("serial: samsung: fix maxburst parameter for DMA transactions")
Cc: stable <stable@kernel.org>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Chanho Park <chanho61.park@samsung.com>
Link: https://lore.kernel.org/r/20220627065113.139520-1-chanho61.park@samsung.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/tty/serial/samsung_tty.c | 5 ++---
1 file changed, 2 insertions(+), 3 deletions(-)

--- a/drivers/tty/serial/samsung_tty.c
+++ b/drivers/tty/serial/samsung_tty.c
@@ -361,8 +361,7 @@ static void enable_tx_dma(struct s3c24xx
/* Enable tx dma mode */
ucon = rd_regl(port, S3C2410_UCON);
ucon &= ~(S3C64XX_UCON_TXBURST_MASK | S3C64XX_UCON_TXMODE_MASK);
- ucon |= (dma_get_cache_alignment() >= 16) ?
- S3C64XX_UCON_TXBURST_16 : S3C64XX_UCON_TXBURST_1;
+ ucon |= S3C64XX_UCON_TXBURST_1;
ucon |= S3C64XX_UCON_TXMODE_DMA;
wr_regl(port, S3C2410_UCON, ucon);

@@ -634,7 +633,7 @@ static void enable_rx_dma(struct s3c24xx
S3C64XX_UCON_DMASUS_EN |
S3C64XX_UCON_TIMEOUT_EN |
S3C64XX_UCON_RXMODE_MASK);
- ucon |= S3C64XX_UCON_RXBURST_16 |
+ ucon |= S3C64XX_UCON_RXBURST_1 |
0xf << S3C64XX_UCON_TIMEOUT_SHIFT |
S3C64XX_UCON_EMPTYINT_EN |
S3C64XX_UCON_TIMEOUT_EN |