MUSB dual-role on AM335x behaving weirdly

[Felipe Balbi]

Hi,

On Wed, Feb 25, 2015 at 01:11:22PM +0100, Yegor Yefremov wrote:
> On 25.02.2015 12:11, Maxime Ripard wrote:
> > On Tue, Feb 24, 2015 at 11:33:57AM -0600, Felipe Balbi wrote:
> >> Hi,
> >>
> >> On Tue, Feb 24, 2015 at 05:50:50PM +0100, Maxime Ripard wrote:
> >>> Hi Felipe,
> >>>
> >>> On Tue, Feb 24, 2015 at 08:54:01AM -0600, Felipe Balbi wrote:
> >>>> Hi,
> >>>>
> >>>> On Tue, Feb 24, 2015 at 11:39:11AM +0100, Maxime Ripard wrote:
> >>>>> On Thu, Feb 05, 2015 at 02:21:42PM +0100, Maxime Ripard wrote:
> >>>>>> Hi,
> >>>>>>
> >>>>>> On Thu, Jan 22, 2015 at 08:37:45AM +0100, Yegor Yefremov wrote:
> >>>>>>> I have the same experience with 3.15. The switching is working when
> >>>>>>> CONFIG_USB_MUSB_DUAL_ROLE is set and dr_mode = "otg". But since 3.16
> >>
> >> since 3.16 ?
> > 
> > That's what Yegor said. I never saw it working with 3.15 either.
> 
> I've used 3.15.1 and 3.15.2 with this set of patches:
> https://github.com/visionsystemsgmbh/onrisc_br_bsp/tree/master/board/vscom/kernel-patches/linux-3.15
> 
> And it worked so far. The system:
> http://www.visionsystems.de/produkte/baltos-ir-5221.html

I've had more time to look into this (thanks Yegor for sponsoring a
test/dev platform) what I noticed is that Connect IRQ takes seconds to
fire up.  Below a tiny log snippet after pluging USB OTG adapter cable
that came with IR5521:

| [ 1227.200514] musb-hdrc musb-hdrc.1.auto: usbintr (100) epintr(0)

Cable connected. ID is grounded. 0x100 == DRVVBUS IRQ

| [ 1227.206788] musb-hdrc musb-hdrc.1.auto: VBUS on (a_wait_vrise), devctl 19

MUSB starts to wait for VBUS to reach Session valid threshold

| [ 1230.281159] musb-hdrc musb-hdrc.1.auto: usbintr (10) epintr(0)

3 seconds later connect interrupt happens. Looking at VBUS charge time
with a scope, it's quite ok. VBUS charges in about 1.77ms. I'll dig
further into this.

-- 
balbi
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