On Fri, Nov 11, 2016 at 01:39:28AM +0200, Laurent Pinchart wrote:
> Hello,
>
> On Friday 11 Nov 2016 00:27:52 Laurent Pinchart wrote:
> > On Thursday 10 Nov 2016 13:42:34 Tony Lindgren wrote:
> > > * Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx> [161110 13:29]:
> > >> I had to disable CONFIG_USB_GADGET is compiling it as a module prevents
> > >> selecting CONFIG_NOP_USB_XCEIV=y, which is a dependency for
> > >> CONFIG_USB_EHCI_HCD_OMAP=m.
> > >>
> > >> The new configuration resulted in a few changes, among which the most
> > >> notable is
> > >>
> > >> -# CONFIG_USB_MUSB_HOST is not set
> > >> -# CONFIG_USB_MUSB_GADGET is not set
> > >> -CONFIG_USB_MUSB_DUAL_ROLE=y
> > >> +CONFIG_USB_MUSB_HOST=y
> > >>
> > >> I then get the same error as originally reported.
> > >
> > > Yeah OK, that's the problem.. We still have musb hardware
> > > trying to do things on it's own and phy trying to detect
> > > the state.
> > >
> > > Any ideas why we have a dependency like that in Kconfig?
> >
> > Well, with CONFIG_USB_GADGET disabled, I don't expect CONFIG_USB_MUSB_GADGET
> > to be enabled. MUSB can only operate in host mode in that case, so musb->
> > xceiv->otg->state = OTG_STATE_A_IDLE makes sense.
>
> I've tried to investigate this but I'm not familiar enough with the MUSB
> driver to reach any conclusion. Felipe, if you have time could you give me a
> hand ?
>
> To summarize the issue, on a pandaboard-es where the MUSB is wired to an OTG
> connector with mode rightfully set to MUSB_PORT_MODE_DUAL_ROLE in DT, a kernel
> configured with CONFIG_USB_MUSB_HOST=y (for instance because CONFIG_USB_GADGET
> is disabled) will print an endless stream of the following meessage.
>
> [ 2.766174] musb_bus_suspend 2586: trying to suspend as a_idle while active
I don't have a omap3/4 platform to test on this, but I don't see this
problem on am335x board.
>
> musb_init_controller() performs the following actions
>
> case MUSB_PORT_MODE_DUAL_ROLE:
> status = musb_host_setup(musb, plat->power);
> if (status < 0)
> goto fail3;
> status = musb_gadget_setup(musb);
> if (status) {
> musb_host_cleanup(musb);
> goto fail3;
> }
> status = musb_platform_set_mode(musb, MUSB_OTG);
> break;
>
> and as gadget support is disabled musb_gadget_setup() compiles to a no-op
> inline function. The system is thus configured in host mode by
> musb_host_setup() with musb->xceiv->otg->state = OTG_STATE_A_IDLE. A later
> call to musb_start() verifies the condition
>
> if (musb->port_mode != MUSB_PORT_MODE_HOST &&
> musb->xceiv->otg->state != OTG_STATE_A_WAIT_BCON &&
> (devctl & MUSB_DEVCTL_VBUS) == MUSB_DEVCTL_VBUS) {
To get there, devctl[MUSB_DEVCTL_VBUS] bits have to be set, where does the
vbus voltage come from? Session is not on yet.
>
> and sets musb->is_active to 1. Later, musb_bus_suspend() complains because
> is_active is not 0.
>
> What is wrong in that sequence ?
>
> --
> Regards,
>
> Laurent Pinchart
>
Regards,
-Bin.
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