This patch adds missing checks for dma_map_single() failure and proper error
reporting. While touching this part of the code, it also removes unnecessary
spinlock calls around dma_map_single() for TX buffer. This finally solves all
the issues reported by DMA API debug framework.
Reported-by: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx>
Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions")
CC: stable@xxxxxxxxxxxxxxx # v4.10+
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx>
---
This issue was there since adding DMA support, but this patch applies cleanly
only to v4.10+ kernels due to other changes in the surrounding code.
v2:
- fixed commit id in 'fixes' tag, added 'reviewed-by' tag
---
drivers/tty/serial/samsung.c | 35 ++++++++++++++++++++++++-----------
1 file changed, 24 insertions(+), 11 deletions(-)
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 9f3759bdb44f..8aca18c4cdea 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -859,7 +859,7 @@ static void s3c24xx_serial_break_ctl(struct uart_port *port, int break_state)
static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
{
struct s3c24xx_uart_dma *dma = p->dma;
- unsigned long flags;
+ int ret;
/* Default slave configuration parameters */
dma->rx_conf.direction = DMA_DEV_TO_MEM;
@@ -884,8 +884,8 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
dma->tx_chan = dma_request_chan(p->port.dev, "tx");
if (IS_ERR(dma->tx_chan)) {
- dma_release_channel(dma->rx_chan);
- return PTR_ERR(dma->tx_chan);
+ ret = PTR_ERR(dma->tx_chan);
+ goto err_release_rx;
}
dmaengine_slave_config(dma->tx_chan, &dma->tx_conf);
@@ -894,25 +894,38 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p)
dma->rx_size = PAGE_SIZE;
dma->rx_buf = kmalloc(dma->rx_size, GFP_KERNEL);
-
if (!dma->rx_buf) {
- dma_release_channel(dma->rx_chan);
- dma_release_channel(dma->tx_chan);
- return -ENOMEM;
+ ret = -ENOMEM;
+ goto err_release_tx;
}
dma->rx_addr = dma_map_single(p->port.dev, dma->rx_buf,
dma->rx_size, DMA_FROM_DEVICE);
-
- spin_lock_irqsave(&p->port.lock, flags);
+ if (dma_mapping_error(p->port.dev, dma->rx_addr)) {
+ ret = -EIO;
+ goto err_free_rx;
+ }
/* TX buffer */
dma->tx_addr = dma_map_single(p->port.dev, p->port.state->xmit.buf,
UART_XMIT_SIZE, DMA_TO_DEVICE);
-
- spin_unlock_irqrestore(&p->port.lock, flags);
+ if (dma_mapping_error(p->port.dev, dma->tx_addr)) {
+ ret = -EIO;
+ goto err_unmap_rx;
+ }
return 0;
+
+err_unmap_rx:
+ dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size,
+ DMA_FROM_DEVICE);
+err_free_rx:
+ kfree(dma->rx_buf);
+err_release_tx:
+ dma_release_channel(dma->tx_chan);
+err_release_rx:
+ dma_release_channel(dma->rx_chan);
+ return ret;
}
static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p)
--
1.9.1
--
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