lkml.org 
[lkml]   [2017]   [Sep]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] serial: imx: only set dma_is_rxing when DMA starts
Date
From: Romain Perier <romain.perier@collabora.com>

The variable dma_is_rxing is currently set to 1 in imx_disable_rx_int().
This is problematic as:

- whilst imx_disable_rx_int() is currently always called before
start_rx_dma() this dependency isn't obvious.
- start_rx_dma() does error checking and might exit without
enabling DMA. Currently this will result in dma_is_rxing suggesting
that DMA is being used for recieving.

To avoid these issues, move the setting of dma_is_rxing to
start_rx_dma() when appropriate.

Signed-off-by: Romain Perier <romain.perier@collabora.com>
Signed-off-by: Martyn Welch <martyn.welch@collabora.co.uk>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
---

This patch has been split out of series: "[PATCH v3 0/6] serial: imx:
various improvements" as this is a stand alone fix and some of the
patches in the series are problematic.

drivers/tty/serial/imx.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index fe368a4..1691ed2 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -714,8 +714,6 @@ static void imx_disable_rx_int(struct imx_port *sport)
{
unsigned long temp;

- sport->dma_is_rxing = 1;
-
/* disable the receiver ready and aging timer interrupts */
temp = readl(sport->port.membase + UCR1);
temp &= ~(UCR1_RRDYEN);
@@ -1074,6 +1072,7 @@ static int start_rx_dma(struct imx_port *sport)
desc->callback_param = sport;

dev_dbg(dev, "RX: prepare for the DMA.\n");
+ sport->dma_is_rxing = 1;
sport->rx_cookie = dmaengine_submit(desc);
dma_async_issue_pending(chan);
return 0;
--
1.8.3.1
\
 
 \ /
  Last update: 2017-09-28 12:05    [W:0.029 / U:10.528 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site