Re: MUSB peripheral DMA regression caused by driver core runtime PM change

[Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>]

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Hi,

Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> writes:
> * Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org> [151023 09:48]:
>> 
>> Hi,
>> 
>> Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org> writes:
>> > From: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>> > Date: Fri, 23 Oct 2015 09:03:22 -0700
>> > Subject: [PATCH] usb: musb: omap2430: Fix regression caused by driver core
>> >  change
>> >
>> > Commit ddef08dd00f5 ("Driver core: wakeup the parent device before trying
>> > probe") started automatically ensuring the parent device is enabled when
>> > the child gets probed.
>> >
>> > This however caused a regression for MUSB omap2430 interface as the
>> > runtime PM for the parent device needs the child initialized to access
>> > the MUSB hardware registers.
>> >
>> > Let's delay the enabling of PM runtime for the parent until the child
>> > has been properly initialized as suggested in an earlier patch by
>> > Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>.
>> >
>> > In addition to delaying pm_runtime_enable, we now also need to make sure
>> > the parent is enabled during omap2430_musb_init. We also want to propagate
>> > an error from omap2430_runtime_resume if struct musb is not initialized.
>> >
>> > Note that we use pm_runtime_put_noidle here for both the child and parent
>> > to prevent an extra runtime_suspend/resume cycle.
>> >
>> > Let's also add some comments to avoid confusion between the
>> > two different devices.
>> >
>> > Fixes: ddef08dd00f5 ("Driver core: wakeup the parent device before
>> > trying probe")
>> > Suggested-by: Grygorii Strashko <grygorii.strashko-l0cyMroinI0@public.gmane.org>
>> > Signed-off-by: Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>
>> 
>> I'm fine with this patch to fix this v4.3 regression. Greg, do you want
>> a pull request or can you take this in as a patch ? In any case:
>> 
>> Acked-by: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>
>
> OK no response for a few days, so I'll pick this up into
> omap-for-v4.3/fixes as I have another fix there too.

all right, thanks


-- 
balbi

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