[U-Boot] [PATCH] MX31: Disable watchdog during low-power modes

[Stefano Babic <sbabic@denx.de>]

On 09/20/2011 06:16 AM, Marek Vasut wrote:
> On Monday, September 19, 2011 07:51:10 PM Fabio Estevam wrote:
>> Turn on the watchdog WDZST bit so that watchdog timer does not count during
>> low power modes.
>>
>> Prior to applying this patch mx31pdk board got watchdog resets because when
>> it booted in the Linux prompt and there was no activity, the system
>> entered into idle mode while watchdog timer was still active.
>>
>> Fix this by disabling watchdog timer during idle mode.
>>
>> Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
>> ---
>>  arch/arm/cpu/arm1136/mx31/timer.c         |    4 ++--
>>  arch/arm/include/asm/arch-mx31/imx-regs.h |    2 ++
>>  2 files changed, 4 insertions(+), 2 deletions(-)
>>
>> diff --git a/arch/arm/cpu/arm1136/mx31/timer.c
>> b/arch/arm/cpu/arm1136/mx31/timer.c index c05a39d..7197108 100644
>> --- a/arch/arm/cpu/arm1136/mx31/timer.c
>> +++ b/arch/arm/cpu/arm1136/mx31/timer.c
>> @@ -173,8 +173,8 @@ void mxc_hw_watchdog_enable(void)
>>  #else
>>  	secs = 64;
>>  #endif
>> -	writew(readw(&wdog->wcr) | (secs << WDOG_WT_SHIFT) | WDOG_ENABLE,
>> -		&wdog->wcr);
>> +	writew(readw(&wdog->wcr) | (secs << WDOG_WT_SHIFT) | WDOG_ENABLE
>> +						| WDOG_WDZST, &wdog->wcr);
> 
> Maybe
> tmp = readw();
> tmp |= ...
> writel(tmp, ...);

Well, I do not see a big difference with your proposal - so it is only a
question of taste. Calling write with an embedded read as first
parameter is used often in u-boot.

Best regards,
Stefano Babic

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