Re: [PATCHv4 3/2] dmaengine: cppi41: Clean up pointless warnings

[Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>]

* Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> [170120 13:08]:
> On Fri, Jan 20, 2017 at 12:07:53PM -0800, Tony Lindgren wrote:
> > With patches "dmaengine: cppi41: Fix runtime PM timeouts with USB mass
> > storage", and "dmaengine: cppi41: Fix oops in cppi41_runtime_resume",
> > the pm_runtime_get/put() in cppi41_irq() is no longer needed. We now
> > guarantee that cppi41 is enabled when dma is in use.
> > 
> > We can still get pointless error -115 when musb is configured as a
> > usb peripheral. That's because we should now check for the state of
> > is_suspended instead.
> 
> I am not sure I understand this paragraph. Do you mean we still get
> harmless -115 in peripheral mode? If so how is it caused by is_suspended
> check? And the comment below for the check implies the WARN_ON() never
> happens...

Yes I noticed we can still get it in peripheral mode. And it's a bogus
warning now because we should now be using the new cdd->is_suspended
instead.

It happens because cppi41_runtime_resume() has not yet completed and is
calling cppi41_run_queue() that produces the interrupt. So that that point
we have cppi41 active with !cdd->is_suspended, but pm_runtime_get() still
returns -EINPROGRESS (115).

Regards,

Tony

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