diff mbox

[v3,4/6] serial: imx: unmap sg buffers when DMA channel is released

Message ID 1506010697-22114-5-git-send-email-martyn.welch@collabora.co.uk (mailing list archive)
State New, archived
Headers show

Commit Message

Martyn Welch Sept. 21, 2017, 4:18 p.m. UTC 
From: Nandor Han <nandor.han@ge.com>

This commits unmaps sg buffers when the DMA channel is released. It also
sets to zero `dma_is_rxing` and `dma_is_txing` to state that the
corresponding channels cannot transmit/receive data, as these are
disabled.

Signed-off-by: Nandor Han <nandor.han@ge.com>
Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
---
 drivers/tty/serial/imx.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

Comments

Uwe Kleine-König Sept. 21, 2017, 6:25 p.m. UTC | #1 
On Thu, Sep 21, 2017 at 05:18:15PM +0100, Martyn Welch wrote:
> From: Nandor Han <nandor.han@ge.com>
> 
> This commits unmaps sg buffers when the DMA channel is released. It also
> sets to zero `dma_is_rxing` and `dma_is_txing` to state that the
> corresponding channels cannot transmit/receive data, as these are
> disabled.

That's a fix for a race, right? The functions being fixed were
introduced just in the patch before and I guess the race was there
already before. It is best if you could resort your series to have fixes
first. This way they can easily be applied during the rc phase while the
rest waits for the merge window.

Best regards
Uwe
diff mbox

Patch

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index 2fb3210..ed02783 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -357,6 +357,12 @@  static void imx_stop_tx_dma(struct imx_port *sport)
 	temp = readl(sport->port.membase + UCR1);
 	temp &= ~UCR1_TDMAEN;
 	writel(temp, sport->port.membase + UCR1);
+
+	if (sport->dma_is_txing) {
+		dma_unmap_sg(sport->port.dev, &sport->tx_sgl[0],
+		sport->dma_tx_nents, DMA_TO_DEVICE);
+		sport->dma_is_txing = 0;
+	}
 }
 
 static void imx_stop_rx_dma(struct imx_port *sport)
@@ -366,6 +372,12 @@  static void imx_stop_rx_dma(struct imx_port *sport)
 	temp = readl(sport->port.membase + UCR1);
 	temp &= ~(UCR1_RDMAEN | UCR1_ATDMAEN);
 	writel(temp, sport->port.membase + UCR1);
+
+	if (sport->dma_is_rxing) {
+		dma_unmap_sg(sport->port.dev, &sport->rx_sgl, 1,
+			DMA_FROM_DEVICE);
+		sport->dma_is_rxing = 0;
+	}
 }
 
 /*