| Message ID | 1490270519-4046-2-git-send-email-m.szyprowski@samsung.com |
|---|---|
| State | New |
| Headers | show |
| Series | [v2,1/2] serial: samsung: Use right device for DMA-mapping calls | expand |
On Thu, Mar 23, 2017 at 01:01:53PM +0100, Marek Szyprowski wrote: > 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@samsung.com> > Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") > CC: stable@vger.kernel.org # v4.10+ > Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> > Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> > --- > 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); Error paths look fine but how about splitting spinlock removal out of this patch? Logically they are two different changes and unrelated code should not be backported. Best regards, Krzysztof -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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)
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@samsung.com> Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") CC: stable@vger.kernel.org # v4.10+ Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> --- 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(-) -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html