[PATCH] usb: dwc3: keystone: switch to use runtime pm

Hi,

On Fri, Jan 31, 2014 at 02:20:48PM -0500, Santosh Shilimkar wrote:

[ snip ]

quoted

note that because of pm_runtime_set_active() that first
pm_runtime_get_sync() in probe() will simply increase the reference
counter without calling my ->runtime_resume() callback, which is exactly
what we want, as that would completely avoid situations of bad context
being restored because of that initial pm_runtime_get_sync().

Thanks for making your point bit clear. 

no problem.

quoted

Then, we can even make pm_runtime completely async easily, because
clk_prepare() was called only on probe() (or before it, for that
matter).

Bottomline is, if you can guarantee me that clk_get(), clk_prepare(),
clk_enable() and pm_runtime_set_active() will be called properly before
my probe, i'll be more than happy to comply with your request above as
that will greatly simplify my driver.

Which is the case at least I see on Keystone. And hence the patch from

I was going over pm_domain.c and drivers/base/power/clock_ops.c and none
of them enable pm_runtime or make sure pm_runtime_set_active() is
called.

Grygorii works. I also noticed your proposal for wider platform to
enforce above behavior which seems to be a good idea.

it'll take months to stabilize though ;-)

quoted

Just make, also, that if this clock is shared between dwc3-keystone
wrapper and dwc3 core, you clk_get() on both driver's probe.

I understand. In summary, whichever patch you pick(yours) or Grygorii's,
its completely safe to remove the clock handling from Keystone USB driver.

alright, since I can't really test, I'll take this as a true statement.
If there are any regressions I can blame you, hehehe.

cheers

-- 
balbi
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