diff options
| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2018-05-10 08:41:13 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-14 13:41:05 +0200 |
| commit | aa2f80e752c75e593b3820f42c416ed9458fa73e (patch) | |
| tree | 8f2bebb6d17d2e10017e3304e1654ea478999825 /drivers/tty | |
| parent | 2ccdb55e52a126aa51a64a2244d8b60c16f370cc (diff) | |
serial: samsung: fix maxburst parameter for DMA transactions
The best granularity of residue that DMA engine can report is in the BURST
units, so the serial driver must use MAXBURST = 1 and DMA_SLAVE_BUSWIDTH_1_BYTE
if it relies on exact number of bytes transferred by DMA engine.
Fixes: 62c37eedb74c ("serial: samsung: add dma reqest/release functions")
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Acked-by: Krzysztof Kozlowski <krzk@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
| -rw-r--r-- | drivers/tty/serial/samsung.c | 7 |
1 files changed, 2 insertions, 5 deletions
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index 3f2f8c118ce0..64e96926f1ad 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -862,15 +862,12 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) dma->rx_conf.direction = DMA_DEV_TO_MEM; dma->rx_conf.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma->rx_conf.src_addr = p->port.mapbase + S3C2410_URXH; - dma->rx_conf.src_maxburst = 16; + dma->rx_conf.src_maxburst = 1; dma->tx_conf.direction = DMA_MEM_TO_DEV; dma->tx_conf.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; dma->tx_conf.dst_addr = p->port.mapbase + S3C2410_UTXH; - if (dma_get_cache_alignment() >= 16) - dma->tx_conf.dst_maxburst = 16; - else - dma->tx_conf.dst_maxburst = 1; + dma->tx_conf.dst_maxburst = 1; dma->rx_chan = dma_request_chan(p->port.dev, "rx"); |