Messages in this thread | | | Date | Fri, 27 Mar 2015 16:15:23 +0100 | From | Javier Martinez Canillas <> | Subject | Re: [RFC PATCH 2/2] ARM: EXYNOS: Make sure that the Exynos5420 MDMA0 clock is enabled during suspend |
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Hello Krzysztof,
Thanks a lot for your feedback.
On 03/27/2015 03:38 PM, Krzysztof Kozlowski wrote: > 2015-03-27 15:21 GMT+01:00 Javier Martinez Canillas > <javier.martinez@collabora.co.uk>: >> Commit ae43b3289186 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power >> Management support v12") added pm support for the pl330 dma driver but >> it makes the clock for the Exynos5420 MDMA0 DMA controller to be gated >> during suspend and this clock needs to remain enabled in order to make >> the system resume from a system suspend state. >> >> To make sure that the clock is enabled during suspend, enable it prior >> to entering a suspend state and disable it once the system has resumed. >> >> Thanks to Abhilash Kesavan for figuring out that this was the issue. >> >> Fixes: ae43b32 ("ARM: 8202/1: dmaengine: pl330: Add runtime Power Management support v12") >> Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> > > Hmmm... isn't a real problem elsewhere - like some clock hierarchy is > wrong or incomplete? This rather looks like workaround for the > problem. >
That's a very good question, that's why I sent it as an RFC. I didn't find anything relevant in the manual but I could certainly be missing something.
>> >> @@ -516,6 +528,9 @@ static void exynos5420_pm_resume(void) >> { >> unsigned long tmp; >> >> + if (!IS_ERR_OR_NULL(clk)) >> + clk_disable_unprepare(clk); >> + > > Missing clk_put() >
Yes, Sylwester already pointed it out. Sorry for missing that.
> Best regards, > Krzysztof >
Best regards, Javier
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