[U-Boot] [PATCH 1/4] ARM: atmel: arm926ejs: fix clock configuration

Heiko Schocher hs at denx.de
Tue Mar 17 09:10:12 CET 2015


Hello Bo,

Am 17.03.2015 08:58, schrieb Bo Shen:
> Hi Heiko,
>
> On 03/17/2015 03:45 PM, Heiko Schocher wrote:
>> Hello Bo,
>>
>> Am 13.03.2015 10:19, schrieb Bo Shen:
>>> Config MCKR according to the datasheet sequence, or else it
>>> will cause the MCKR configuration failed.
>>>
>>> Remove timeout checking for clock configuration, if configure
>>> the clock failed, let the system hang while not run in wrong
>>> clock configuration.
>>>
>>> Signed-off-by: Bo Shen <voice.shen at atmel.com>
>>> ---
>>>
>>>   arch/arm/mach-at91/arm926ejs/clock.c | 54
>>> +++++++++++++++++++-----------------
>>>   1 file changed, 28 insertions(+), 26 deletions(-)
>>
>> Tested on the corvus and taurus board.
>>
>> Tested-by: Heiko Schocher <hs at denx.de>
>
> Thanks.
>
>>> diff --git a/arch/arm/mach-at91/arm926ejs/clock.c
>>> b/arch/arm/mach-at91/arm926ejs/clock.c
>>> index f363982..8d6934e 100644
>>> --- a/arch/arm/mach-at91/arm926ejs/clock.c
>>> +++ b/arch/arm/mach-at91/arm926ejs/clock.c
>>> @@ -195,50 +195,52 @@ int at91_clock_init(unsigned long main_clock)
>>>   void at91_plla_init(u32 pllar)
>>>   {
>>>       struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
>>> -    int timeout = AT91_PLL_LOCK_TIMEOUT;
>>>
>>>       writel(pllar, &pmc->pllar);
>>> -    while (!(readl(&pmc->sr) & (AT91_PMC_LOCKA | AT91_PMC_MCKRDY))) {
>>> -        timeout--;
>>> -        if (timeout == 0)
>>> -            break;
>>> -    }
>>> +    while (!(readl(&pmc->sr) & AT91_PMC_LOCKA))
>>> +        ;
>>
>> just hanging is maybe also bad ... could we hang with adding a
>>
>>          if (timeout == 0) {
>>              debug("could not set PLL(A|B)\n");
>>              timeout = AT91_PLL_LOCK_TIMEOUT;
>>          }
>>
>> Thinking about it ... have we setup here the debug uart already?
>> If not, forget my comment
>
> Yes the uart is not ready. And one more thing, if the clock is not setup correctly, then the system will run in abnormal status. So, I remove the timeout check here.

Ok, thanks!

bye,
Heiko
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