diff mbox

[v3,16/33] serial: sh-sci: Use correct device for DMA mapping with IOMMU

Message ID 1440180177-6924-17-git-send-email-geert+renesas@glider.be (mailing list archive)
State Accepted
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Geert Uytterhoeven Aug. 21, 2015, 6:02 p.m. UTC 
To function correctly in the presence of an IOMMU, the DMA buffers must
be managed using the DMA channel's device instead of the platform
device's device.

Make sure to free the DMA memory before releasing the channel, not
after.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---
v3:
  - Fix call to dma_sync_sg_for_device() which I missed before,
  - Rebased on top of "serial: sh-sci: Handle DMA init failures inside
    sci_request_dma()",

v2:
  - Add Acked-by.
---
 drivers/tty/serial/sh-sci.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)
diff mbox

Patch

diff --git a/drivers/tty/serial/sh-sci.c b/drivers/tty/serial/sh-sci.c
index ea6ab6173ce9f239..9aa9720d7f09d10f 100644
--- a/drivers/tty/serial/sh-sci.c
+++ b/drivers/tty/serial/sh-sci.c
@@ -1370,9 +1370,9 @@  static void sci_rx_dma_release(struct sci_port *s, bool enable_pio)
 
 	s->chan_rx = NULL;
 	s->cookie_rx[0] = s->cookie_rx[1] = -EINVAL;
-	dma_release_channel(chan);
-	dma_free_coherent(port->dev, s->buf_len_rx * 2,
+	dma_free_coherent(chan->device->dev, s->buf_len_rx * 2,
 			  sg_virt(&s->sg_rx[0]), sg_dma_address(&s->sg_rx[0]));
+	dma_release_channel(chan);
 	if (enable_pio)
 		sci_start_rx(port);
 }
@@ -1523,7 +1523,7 @@  static void work_fn_tx(struct work_struct *work)
 		return;
 	}
 
-	dma_sync_sg_for_device(port->dev, sg, 1, DMA_TO_DEVICE);
+	dma_sync_sg_for_device(chan->device->dev, sg, 1, DMA_TO_DEVICE);
 
 	spin_lock_irq(&port->lock);
 	s->desc_tx = desc;
@@ -1705,7 +1705,8 @@  static void sci_request_dma(struct uart_port *port)
 		sg_set_page(&s->sg_tx, virt_to_page(port->state->xmit.buf),
 			    UART_XMIT_SIZE,
 			    (uintptr_t)port->state->xmit.buf & ~PAGE_MASK);
-		nent = dma_map_sg(port->dev, &s->sg_tx, 1, DMA_TO_DEVICE);
+		nent = dma_map_sg(chan->device->dev, &s->sg_tx, 1,
+				  DMA_TO_DEVICE);
 		if (!nent) {
 			dev_warn(port->dev, "Failed mapping Tx DMA descriptor\n");
 			dma_release_channel(chan);
@@ -1737,8 +1738,9 @@  static void sci_request_dma(struct uart_port *port)
 		s->chan_rx = chan;
 
 		s->buf_len_rx = 2 * max(16, (int)port->fifosize);
-		buf[0] = dma_alloc_coherent(port->dev, s->buf_len_rx * 2,
-					    &dma[0], GFP_KERNEL);
+		buf[0] = dma_alloc_coherent(chan->device->dev,
+					    s->buf_len_rx * 2, &dma[0],
+					    GFP_KERNEL);
 
 		if (!buf[0]) {
 			dev_warn(port->dev,