Re: [PATCH V6 01/21] irqchip: tegra: Do not disable COP IRQ during suspend

[Dmitry Osipenko]

25.07.2019 13:38, Peter De Schrijver ÐÐÑÐÑ:
> On Thu, Jul 25, 2019 at 01:33:48PM +0300, Peter De Schrijver wrote:
>> On Thu, Jul 25, 2019 at 01:05:13PM +0300, Dmitry Osipenko wrote:
>>> 25.07.2019 12:55, Peter De Schrijver ÐÐÑÐÑ:
>>>> On Mon, Jul 22, 2019 at 12:54:51PM +0300, Dmitry Osipenko wrote:
>>>>>
>>>>> All Tegra SoCs support SC7, hence the 'supports_sc7' and the comment
>>>>> doesn't sound correct to me. Something like 'firmware_sc7' should suit
>>>>> better here.
>>>>>
>>>>>> +			writel_relaxed(~0ul, ictlr + ICTLR_COP_IER_CLR);
>>>>>
>>>>> Secondly, I'm also not sure why COP interrupts need to be disabled for
>>>>> pre-T210 at all, since COP is unused. This looks to me like it was
>>>>> cut-n-pasted from downstream kernel without a good reason and could be
>>>>> simply removed.
>>>>
>>>> I don't think we can rely on the fact that COP is unused. People can
>>>> write their own code to run on COP.
>>>
>>> 1. Not upstream - doesn't matter.
>>>
>>
>> The code is not part of the kernel, so obviously it's not upstream?
>>
>>> 2. That's not very good if something unknown is running on COP and then
>>> kernel suddenly intervenes, don't you think so?
>>
>> Unless the code was written with this in mind.
>>

In that case, please see 1. ;)

> 
> Looking at this again, I don't think we need to enable the IRQ at all.

Could you please clarify? The code only saves/restores COP's interrupts
context across suspend-resume.

Again, that's absolutely useless code for the upstream kernel which
could be removed safely to avoid the confusion, IMHO. I can type a patch
if you're agreeing.