From 768d64f491a530062ddad50e016fb27125f8bd7c Mon Sep 17 00:00:00 2001 From: Marek Szyprowski Date: Mon, 3 Apr 2017 08:20:59 +0200 Subject: [PATCH] serial: samsung: Use right device for DMA-mapping calls Driver should provide its own struct device for all DMA-mapping calls instead of extracting device pointer from DMA engine channel. Although this is harmless from the driver operation perspective on ARM architecture, it is always good to use the DMA mapping API in a proper way. This patch fixes following DMA API debug warning: WARNING: CPU: 0 PID: 0 at lib/dma-debug.c:1241 check_sync+0x520/0x9f4 samsung-uart 12c20000.serial: DMA-API: device driver tries to sync DMA memory it has not allocated [device address=0x000000006df0f580] [size=64 bytes] Modules linked in: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.11.0-rc1-00137-g07ca963 #51 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x20/0x24) [] (show_stack) from [] (dump_stack+0x84/0xa0) [] (dump_stack) from [] (__warn+0x14c/0x180) [] (__warn) from [] (warn_slowpath_fmt+0x48/0x50) [] (warn_slowpath_fmt) from [] (check_sync+0x520/0x9f4) [] (check_sync) from [] (debug_dma_sync_single_for_device+0x88/0xc8) [] (debug_dma_sync_single_for_device) from [] (s3c24xx_serial_start_tx_dma+0x100/0x2f8) [] (s3c24xx_serial_start_tx_dma) from [] (s3c24xx_serial_tx_chars+0x198/0x33c) Reported-by: Seung-Woo Kim Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") CC: stable@vger.kernel.org # v4.0+ Signed-off-by: Marek Szyprowski Reviewed-by: Bartlomiej Zolnierkiewicz Reviewed-by: Krzysztof Kozlowski Reviewed-by: Shuah Khan Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/samsung.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c index 7a17aedbf902..9f3759bdb44f 100644 --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -901,14 +901,13 @@ static int s3c24xx_serial_request_dma(struct s3c24xx_uart_port *p) return -ENOMEM; } - dma->rx_addr = dma_map_single(dma->rx_chan->device->dev, dma->rx_buf, + 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); /* TX buffer */ - dma->tx_addr = dma_map_single(dma->tx_chan->device->dev, - p->port.state->xmit.buf, + 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); @@ -922,7 +921,7 @@ static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p) if (dma->rx_chan) { dmaengine_terminate_all(dma->rx_chan); - dma_unmap_single(dma->rx_chan->device->dev, dma->rx_addr, + dma_unmap_single(p->port.dev, dma->rx_addr, dma->rx_size, DMA_FROM_DEVICE); kfree(dma->rx_buf); dma_release_channel(dma->rx_chan); @@ -931,7 +930,7 @@ static void s3c24xx_serial_release_dma(struct s3c24xx_uart_port *p) if (dma->tx_chan) { dmaengine_terminate_all(dma->tx_chan); - dma_unmap_single(dma->tx_chan->device->dev, dma->tx_addr, + dma_unmap_single(p->port.dev, dma->tx_addr, UART_XMIT_SIZE, DMA_TO_DEVICE); dma_release_channel(dma->tx_chan); dma->tx_chan = NULL; -- 2.20.1