Re: [PATCH 3/6] drm/i915: reset eDP timestamps on resume

Paulo Zanoni
2014-01-17T21:11:15Z

2014/1/17 Chris Wilson <chris@chris-wilson.co.uk>:
> On Fri, Jan 17, 2014 at 06:17:42PM -0200, Paulo Zanoni wrote:
>> From: Paulo Zanoni <paulo.r.zanoni@intel.com>
>>
>> The eDP code records a few timestamps containing the last time we took
>> some actions, because we need to wait before doing some other actions.
>> The problem is that if we store a timestamp when suspending and then
>> look at it when resuming, we'll ignore the unknown amount of time we
>> actually were suspended.
>>
>> This happens with the panel power cycle delay: it's 500ms on my
>> machine, and it's delaying the resume sequence by 200ms due to a
>> timestamp we recorded before suspending. This patch should solve this
>> problem by resetting the timestamps.
>
> But you don't explain why this is safe. The code nerfs the timeouts so
> that they are ignored, yet the delays are independent. Should this be
> based on realtime rather than jiffies?

I'm not sure I understand your question. What's the problem you see exactly?

Thanks,
Paulo

> -Chris
>
> --
> Chris Wilson, Intel Open Source Technology Centre

--
Paulo Zanoni