[U-Boot] U-Boot Rockchip dwc_hcd question for low-speed devices

[Josh Sanford]

Thanks Simon,

I've been looking through the code you referenced.  So these patches are
just standalone snippets and not yet part of any branch?  (I'm just not
familiar with U-Boot's development process.)

Josh

On Tue, Jan 5, 2016 at 7:25 PM, Simon Glass <sjg at chromium.org> wrote:

> Hi Josh,
>
> On 21 December 2015 at 07:11, Josh Sanford <joshs6502 at gmail.com> wrote:
> > Thanks Simon.  I'm having difficulty finding anything by Stefan Bruns
> around
> > that time frame, or much of anything recent pertaining to DWC.  (I only
> > checked the u-boot-denx.git and u-boot-rockchip.git branches.)  Am I
> looking
> > in the wrong place?
>
> This is just patches at present - see here:
>
> http://patchwork.ozlabs.org/project/uboot/list/?submitter=67055&state=*
>
> Regards,
> Simon
>
> >
> > On Sat, Dec 19, 2015 at 3:30 PM, Simon Glass <sjg at chromium.org> wrote:
> >>
> >> +Marek, Stephen
> >>
> >> Hi Josh,
> >>
> >> On 18 December 2015 at 06:26, Josh Sanford <joshs6502 at gmail.com> wrote:
> >> > All,
> >> >
> >> > I am trying to use USB within U-Boot on a Firefly RK3288 (Rockchip)
> >> > board,
> >> > and I am able to enumerate high-speed devices, but not full-speed or
> >> > low-speed devices.  I know that the devices are functional, because
> they
> >> > work on the same physical hardware when I boot into Linux.  Note that
> >> > I'm
> >> > using "U-Boot 2014.10-RK3288-02".
> >> >
> >> > As an aside, the built-in "USB 2.0 Hub [MTT]" hub never generates a
> >> > USB_PORT_STAT_C_CONNECTION for me, even though
> USB_PORT_STAT_CONNECTION
> >> > goes
> >> > high immediately after powering on, so I forcibly assert
> >> > USB_PORT_STAT_C_CONNECTION to allow the rest of the tree to enumerate.
> >> >
> >> > High-speed devices can be nested as deeply as I wish and still show up
> >> > properly, but I can't get low-speed devices (i.e. a keyboard) to work
> in
> >> > any
> >> > hub port, including any of the ports directly on the board.  All
> >> > attempts to
> >> > read from my low-speed devices return all zeros.  When I dig a little
> >> > deeper, I find myself in int dwc_wait_for_complete(struct usb_device
> >> > *dev,
> >> > uint32_t channel_num, uint32_t *hcStat, uint32_t *errCnt) {}.
> >> >
> >> > On the second iteration through the goto loop, hcintn.b.chhltd and
> >> > hcintn.b.xacterr are both asserted, but hcintn.b.ack, hcintn.b.nak,
> and
> >> > hcintn.b.nyet are not, and errCnt is only 1, so the code sets *hcStat
> =
> >> > HCSTAT_REINIT and returns.
> >> >
> >> > I do notice that dwc_hcd.c seems not to have any code to support split
> >> > transactions (or perhaps I simply haven't seen it yet).  If true, I
> >> > wonder
> >> > whether this code is actually expected to support full-speed and
> >> > low-speed
> >> > devices.  Do you have any thoughts on the matter?  I wish I were more
> of
> >> > a
> >> > USB expert, but I'm regrettably quite a novice.
> >>
> >> I believe the split transaction issue is currently being resolved for
> >> DWC. See for example Stefan Bruns' series from 13th December. It might
> >> be worth trying that out.
> >>
> >> Regards,
> >> Simon
> >
> >
>