Re: [PATCHv2] usb: musb: Fix unbalanced platform_disable

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

* Bin Liu <b-liu-l0cyMroinI0@public.gmane.org> [160912 09:55]:
> Hi Tony,
> 
> On Mon, Sep 12, 2016 at 08:39:49AM -0700, Tony Lindgren wrote:
> > Commit a83e17d0f73b ("usb: musb: Improve PM runtime and phy handling
> > for 2430 glue layer") moved PHY enable/disable calls to happen from
> > omap2430_musb_enable/disable(). That broke enumeration for several
> > devices as PM runtime in the PHY will never enable it.
> > 
> > The root cause of the problem is unpaired calls from musb_core.c to
> > musb_platform_enable/disable in musb_core.c as reported by
> > Andreas Kemnade <andreas-cLv4Z9ELZ06ZuzBka8ofvg@public.gmane.org>.
> > 
> > As musb_platform_enable/disable are being called from various functions,
> > let's not attempt to make them paiered immediately. This would require
> > fixing all the callers like musb_remove.
> > 
> > Instead, let's first fix the regression in a minimal way by removing
> > the initial call to musb_platform_disable.
> > 
> > AFAIK the initial musb_platform_disable call has always been just an
> > attempted workaround for the 2430 glue layer announcing itself too
> > early before the gadgets are configured. And that issue finally
> 
> Many glue layers rely on musb_platform_diable to disable interrupts in
> musb_init_controller() before registering ISR, is it safe to assume the
> interrupts will be masked when musb is out-of-reset so that we don't
> have to call musb_platform_disable() in musb_init_controller()?

It should be, we do request_irq only later on after this in musb_core.c.
And the glue layers don't do request_irq except for the separate DMA
interrupts in two cases.

And as the platform glue layer are the ones doing the probing, they
should initialize things into sane state :)

We could add a call irq_set_status_flags(irq, IRQ_NOAUTOEN) before
request_irq. But I'm guessing there's no need to.. Do you have some
example in mind that should be tested?

Regards,

Tony
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