This is a note to let you know that I've just added the patch titled serial: samsung: Use right device for DMA-mapping calls to the 4.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: serial-samsung-use-right-device-for-dma-mapping-calls.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 768d64f491a530062ddad50e016fb27125f8bd7c Mon Sep 17 00:00:00 2001 From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Date: Mon, 3 Apr 2017 08:20:59 +0200 Subject: serial: samsung: Use right device for DMA-mapping calls From: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> commit 768d64f491a530062ddad50e016fb27125f8bd7c upstream. 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) [<c011aaa4>] (unwind_backtrace) from [<c01127c0>] (show_stack+0x20/0x24) [<c01127c0>] (show_stack) from [<c06ba5d8>] (dump_stack+0x84/0xa0) [<c06ba5d8>] (dump_stack) from [<c0139528>] (__warn+0x14c/0x180) [<c0139528>] (__warn) from [<c01395a4>] (warn_slowpath_fmt+0x48/0x50) [<c01395a4>] (warn_slowpath_fmt) from [<c0729058>] (check_sync+0x520/0x9f4) [<c0729058>] (check_sync) from [<c072967c>] (debug_dma_sync_single_for_device+0x88/0xc8) [<c072967c>] (debug_dma_sync_single_for_device) from [<c0803c10>] (s3c24xx_serial_start_tx_dma+0x100/0x2f8) [<c0803c10>] (s3c24xx_serial_start_tx_dma) from [<c0804338>] (s3c24xx_serial_tx_chars+0x198/0x33c) Reported-by: Seung-Woo Kim <sw0312.kim@xxxxxxxxxxx> Fixes: 62c37eedb74c8 ("serial: samsung: add dma reqest/release functions") Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Reviewed-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@xxxxxxxxxxx> Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx> Reviewed-by: Shuah Khan <shuahkh@xxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/tty/serial/samsung.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/drivers/tty/serial/samsung.c +++ b/drivers/tty/serial/samsung.c @@ -906,14 +906,13 @@ static int s3c24xx_serial_request_dma(st 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); @@ -927,7 +926,7 @@ static void s3c24xx_serial_release_dma(s 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); @@ -936,7 +935,7 @@ static void s3c24xx_serial_release_dma(s 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; Patches currently in stable-queue which might be from m.szyprowski@xxxxxxxxxxx are queue-4.10/serial-samsung-use-right-device-for-dma-mapping-calls.patch