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authorIan Jamison <ian.dev@arkver.com>2017-08-28 09:02:29 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-08-28 20:51:22 +0200
commit5aabd3b0077e0577f60a1ca6b8bdad62f23353d8 (patch)
tree37925cc552690d5c32604e8d06d30ad061422f61
parent81b289cc14ba349cc4707cf664aa1c72d7dff1d7 (diff)
downloadlinux-5aabd3b0077e0577f60a1ca6b8bdad62f23353d8.tar.bz2
serial: imx: Avoid post-PIO cleanup if TX DMA is started
The imx_transmit_buffer function should return if TX DMA has already been started and not just skip over the buffer PIO write loop. (Which did fix the initial problem, but could have unintentional side-effects) Tested on an i.MX6Q board with half-duplex RS-485 and with RS-232. Cc: Clemens Gruber <clemens.gruber@pqgruber.com> Cc: Uwe-Kleine König <u.kleine-koenig@pengutronix.de> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Fabio Estevam <fabio.estevam@nxp.com> Fixes: 514ab34dbad6 ("serial: imx: Prevent TX buffer PIO write when a DMA has been started") Signed-off-by: Ian Jamison <ian.dev@arkver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/tty/serial/imx.c5
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
index d879a9b86424..dfeff3951f93 100644
--- a/drivers/tty/serial/imx.c
+++ b/drivers/tty/serial/imx.c
@@ -457,7 +457,10 @@ static inline void imx_transmit_buffer(struct imx_port *sport)
}
}
- while (!uart_circ_empty(xmit) && !sport->dma_is_txing &&
+ if (sport->dma_is_txing)
+ return;
+
+ while (!uart_circ_empty(xmit) &&
!(readl(sport->port.membase + uts_reg(sport)) & UTS_TXFULL)) {
/* send xmit->buf[xmit->tail]
* out the port here */