| Message ID | 1437070920-28069-6-git-send-email-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | RFC |
| Delegated to: | Geert Uytterhoeven |
| Headers | show |
diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c index 6431b1fb9c162e77..8ffc6320ff0a8448 100644 --- a/drivers/tty/serial/sh-sci.c +++ b/drivers/tty/serial/sh-sci.c @@ -1390,6 +1390,14 @@ static void sci_tx_dma_release(struct sci_port *s, bool enable_pio) s->chan_tx = NULL; s->cookie_tx = -EINVAL; + if (s->sg_len_tx) { + /* Restore sg_dma_len() and sg_dma_address() */ + sg_dma_len(&s->sg_tx) = UART_XMIT_SIZE; + sg_dma_address(&s->sg_tx) = sg_dma_address(&s->sg_tx) & + ~(UART_XMIT_SIZE - 1); + dma_unmap_sg(chan->device->dev, &s->sg_tx, 1, DMA_TO_DEVICE); + s->sg_len_tx = 0; + } dma_release_channel(chan); if (enable_pio) sci_start_tx(port);
The mapped scatterlist is never unmapped. This leaks quite some mappings, as the mapping is done in uart_ops.startup(), i.e. every time the device is opened. Unmap the scatterlist on device close. Note that we have to restore the original DMA entry length and DMA address, as it has been modified in work_fn_tx(). Else warnings are printed if CONFIG_DMA_API_DEBUG=y: WARNING: CPU: 0 PID: 20 at lib/dma-debug.c:1103 check_unmap+0x24c/0x85c() rcar-dmac e6700000.dma-controller: DMA-API: device driver frees DMA memory with different size [device address=0x000000006e15f000] [map size=4096 bytes] [unmap size=3 bytes] and: WARNING: CPU: 0 PID: 1364 at lib/dma-debug.c:1093 check_unmap+0x178/0x85c() rcar-dmac e6700000.dma-controller: DMA-API: device driver tries to free DMA memory it has not allocated [device address=0x000000006e16b006] [size=4096 bytes] TODO: Simplify by switching to dma_map_single(), as the transmit scatterlist contains one single entry, which is reused and modified. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- v2: - Add TODO --- drivers/tty/serial/sh-sci.c | 8 ++++++++ 1 file changed, 8 insertions(+)