[U-Boot] [PATCH 0/2] sunxi: musb: Fix "usb reset" handling

Maxime Ripard maxime.ripard at free-electrons.com
Fri Jun 26 13:11:27 CEST 2015


On Fri, Jun 26, 2015 at 01:02:51PM +0200, Hans de Goede wrote:
> Hi,
> 
> On 26-06-15 12:20, Maxime Ripard wrote:
> >Hi,
> >
> >On Sun, Jun 14, 2015 at 12:40:11PM +0200, Hans de Goede wrote:
> >>Paul, can you test these with gadget mode? Specifically if they help the
> >>problem you were seeing when switching roles?
> >>
> >>Also this bit from the kernel code for the sunxi glue may be relevant
> >>to your problems:
> >>
> >>         if ((musb->int_usb & MUSB_INTR_RESET) && !is_host_active(musb)) {
> >>                 /* ep0 FADDR must be 0 when (re)entering peripheral mode */
> >>                 musb_ep_select(musb->mregs, 0);
> >>                 musb_writeb(musb->mregs, MUSB_FADDR, 0);
> >>         }
> >>
> >>This is from the interrupt handler in the sunxi-musb glue in the kernel,
> >>maybe we can do the same, and/or maybe we need to do:
> >>
> >>	/* ep0 FADDR must be 0 when (re)entering peripheral mode */
> >>	musb_ep_select(musb->mregs, 0);
> >>	musb_writeb(musb->mregs, MUSB_FADDR, 0);
> >>
> >> From sunxi_musb_disable?
> >
> >So, I was affected by this issue on a SinA33, even when not switching
> >roles (since the SinA33 is peripheral only).
> 
> Missed this the first reply, are you sure, that is somewhat weird. I mean
> it is possible if they did not hook up the id pin, or do not allow you
> to send out +5v, but it is weird. I guess they did route the real usb-host
> to an USB-A receptacle on that board, so it is not a big deal, right ?

Yeah, I'm sure, or at least that's what the schematics say. VBUS comes
straight from the DC-5V (without any GPIO in between), goes through a
jumper (you read me right....), which is even un-populated on the
boards Chen-Yu and I got.

So it seems like while the board has the ID pin routed, it's actually
not able to provide VBUS (which is kind of weird, but anyway).

Maxime

-- 
Maxime Ripard, Free Electrons
Embedded Linux, Kernel and Android engineering
http://free-electrons.com
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