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From: dirk.behme@de•bosch.com (Dirk Behme)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH 2/2] tty: serial: imx: don't reinit clock with enabled console
Date: Tue, 28 Aug 2012 12:46:27 +0200	[thread overview]
Message-ID: <503CA183.70704@de.bosch.com> (raw)
In-Reply-To: <503BBA5A.8040609@boundarydevices.com>

On 27.08.2012 20:20, Troy Kisky wrote:
> On 8/27/2012 12:36 AM, Dirk Behme wrote:
>> From: Xinyu Chen <xinyu.chen@freescale•com>
>>
>> Remove the imx_setup_ufcr() call on startup when CONSOLE enabled,
>> as this will cause clock reinit, and output garbage.
>>
>> This patch is a port from Freescale's Android kernel.
>>
>> Signed-off-by: Xinyu Chen <xinyu.chen@freescale•com>
>> Tested-by: Dirk Behme <dirk.behme@de•bosch.com>
>> CC: Shawn Guo <shawn.guo@linaro•org>
>> CC: Sascha Hauer <s.hauer@pengutronix•de>
>> ---
>>   drivers/tty/serial/imx.c |    2 ++
>>   1 files changed, 2 insertions(+), 0 deletions(-)
>>
>> diff --git a/drivers/tty/serial/imx.c b/drivers/tty/serial/imx.c
>> index 908178f..31ce414 100644
>> --- a/drivers/tty/serial/imx.c
>> +++ b/drivers/tty/serial/imx.c
>> @@ -695,7 +695,9 @@ static int imx_startup(struct uart_port *port)
>>   	int retval;
>>   	unsigned long flags, temp;
>>   
>> +#ifndef CONFIG_SERIAL_CORE_CONSOLE
>>   	imx_setup_ufcr(sport, 0);
>> +#endif
>>   
>>   	/* disable the DREN bit (Data Ready interrupt enable) before
>>   	 * requesting IRQs
> 
> 
> I'd rather do something like this
> 
> static int imx_setup_ufcr(struct imx_port *sport, unsigned int mode)
> {
>          unsigned int val;
> 
>          /* set receiver / transmitter trigger level. */
>          val = readl(sport->port.membase + UFCR) & UFCR_RFDIV;

Shouldn't it be

... & (UFCR_RFDIV | UFCR_DCEDTE);

then? My i.MX6 manual has DCEDTE as bit 6, which we don't want to touch, 
too? We only want to touch TXTL and RXTL?

>          val |= TXTL << 10 | RXTL;
>          writel(val, sport->port.membase + UFCR);
>          return 0;
> }
> 
> There is no need for imx_setup_ufcr to change divisor.

Ok

Thanks

Dirk

  reply	other threads:[~2012-08-28 10:46 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-08-27  7:36 [PATCH 0/2] tty: serial: imx: fix lockup and garbage on SMP Dirk Behme
2012-08-27  7:36 ` [PATCH 1/2] tty: serial: imx: console write routing is unsafe " Dirk Behme
2012-08-27 22:33   ` Shawn Guo
2012-08-27  7:36 ` [PATCH 2/2] tty: serial: imx: don't reinit clock with enabled console Dirk Behme
2012-08-27 18:20   ` Troy Kisky
2012-08-28 10:46     ` Dirk Behme [this message]
2012-08-28 18:27       ` Troy Kisky
2012-08-28 18:45         ` Troy Kisky
2012-08-27 22:31 ` [PATCH 0/2] tty: serial: imx: fix lockup and garbage on SMP Shawn Guo
2012-08-27 22:51   ` Greg Kroah-Hartman
2012-08-27 23:37     ` Shawn Guo
2012-08-28  6:03       ` Dirk Behme

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