Re: [PATCH 1/2] serial: mxs-auart: fix the wrong setting order

From: Huang Shijie
Date: Thu Sep 06 2012 - 22:41:51 EST


ä 2012å09æ07æ 10:38, Shawn Guo åé:
On Thu, Sep 06, 2012 at 10:38:40PM -0400, Huang Shijie wrote:
After set the AUART_CTRL0_CLKGATE, the UART will gate all the clocks off.
So the following line will not take effect.
................................................................
writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
u->membase + AUART_INTR_CLR);
................................................................

To fix this issue, the patch moves this gate-off line to
the end of setting registers.

Signed-off-by: Huang Shijie<shijie8@xxxxxxxxx>
Acked-by: Shawn Guo<shawn.guo@xxxxxxxxxx>

Are you experiencing any user visible problem with this bug?

I do not experience any user problem.
I found this bug when i tried to add DMA support for MXS-AUART.

Best Regards
Huang Shijie


Regards,
Shawn

---
drivers/tty/serial/mxs-auart.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/mxs-auart.c b/drivers/tty/serial/mxs-auart.c
index dafeef2..ea5f888 100644
--- a/drivers/tty/serial/mxs-auart.c
+++ b/drivers/tty/serial/mxs-auart.c
@@ -457,11 +457,11 @@ static void mxs_auart_shutdown(struct uart_port *u)

writel(AUART_CTRL2_UARTEN, u->membase + AUART_CTRL2_CLR);

- writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
-
writel(AUART_INTR_RXIEN | AUART_INTR_RTIEN | AUART_INTR_CTSMIEN,
u->membase + AUART_INTR_CLR);

+ writel(AUART_CTRL0_CLKGATE, u->membase + AUART_CTRL0_SET);
+
clk_disable_unprepare(s->clk);
}

--
1.7.4.4

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