MUSB dual-role on AM335x behaving weirdly

[Bin Liu]

Felipe,

On Thu, May 14, 2015 at 2:04 PM, Felipe Balbi <balbi at ti.com> wrote:
> On Thu, May 14, 2015 at 12:49:07PM -0500, Felipe Balbi wrote:
>> On Thu, May 14, 2015 at 12:40:31PM -0500, Felipe Balbi wrote:
>> > On Thu, May 14, 2015 at 12:07:00PM -0500, Felipe Balbi wrote:
>> > > 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.
>> >
>> > even more weird. If I disconnect device from OTG adapter, rather than
>> > OTG adapter from IR5521, this leave ID pin grounded, which means DRVVBUS
>> > is still asserted and VBUS remains above session valid threshold.
>> >
>> > Even in this case, when I connect the device on the other end of the
>> > cable, I still see some 3 seconds delay from the time device is
>> > connected, to the time connect IRQ fires up.
>>
>> seems to be a problem with the USB stick I'm using. Tested two other
>> devices and they connect right away.
>
> ok, fixing DRD on AM335x will take longer than I originally expected,
> probably won't be ready for v4.2 :-(

Are you able replicate the issue with TI AM335x GP EVM? I am wondering
if the is custom board design problem? have you checked the custom
board schematics?

Regards,
-Bin.

>
> --
> balbi