Re: [PATCH] ARM: OMAP1: PM: fix some build warnings on 1510-only Kconfigs

From: Jon Hunter
Date: Thu Feb 12 2015 - 06:26:54 EST



On 02/11/2015 09:14 PM, Tony Lindgren wrote:
> * Paul Walmsley <paul@xxxxxxxxx> [150211 13:03]:
>> On Wed, 11 Feb 2015, Tony Lindgren wrote:
>>
>>> * Paul Walmsley <paul@xxxxxxxxx> [150210 18:28]:
>>>> On Tue, 10 Feb 2015, Jon Hunter wrote:
>>>>> On 07/02/2015 00:23, Paul Walmsley wrote:
>>>>
>>>>> Unfortunately, there is not a single TRM for the omap5910 but individual
>>>>> documents for each chapter in the original TRM. Check out the "OMAP5910
>>>>> Dual-Core Processor Timer Reference Guide" and possibly the "OMAP5910
>>>>> Dual-Core Processor Clock Generation and System Reset Management
>>>>> Reference Guide"
>>>>>
>>>>> The omap15xx/5910 did have a 32k timer but as you can see it appears it
>>>>> was never supported by the kernel for this device (not sure why). I do
>>>>> recall that there is some errata regarding the 32k timer, if you look at
>>>>> the omap5910 errata document and search for 32k you should find it.
>>>>
>>>> OK thanks for the context. I probably am not going to investigate adding
>>>> support for this timer on OMAP1510/5910 - am primarily trying to avoid
>>>> causing a regression on the existing platforms.
>>>
>>> At least I've never seen the 32KiHz timer registers in any 15xx
>>> documentation. Jon are you sure you're not mixing up 5910 (15xx)
>>> and 5912 (16xx)?
>>
>> It's documented in the OMAP5910 Timer Reference Guide (SPRU682A) Section 3
>> "32-kHz Timer", at the link Jon mentioned. Have not checked the errata
>> that Jon mentioned though.
>
> Interesting. Looks like it's the same as on 16xx at 0xfffb9000.
> AFAIK that never worked on 15xx. Or maybe the issue was that 15xx
> is missing the constantly running 32KiHz counter making the timer
> unusable from PM point of view as the clockevent alone is not enough.
>
>> Regarding the patch: I'd suggest keeping the compilation warning fixes
>> (which was the original purpose of the patch) from anything that changes
>> the logic too much. That way if there's an error in the patch that
>> changes the logic and it needs to be reverted, it won't also revert the
>> warning fixes.
>
> Makes sense to me.

Yes that's fine with me as well, I don't wish to over complicate
matters. I have a couple minor comments though and will respond to the
latest patch rev.

Cheers
Jon


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