[PATCH v1 1/1] usb: ci_udc: don't use "advance" feature when setting address

[Ion Agorria]

Hello,

Yes that's the correct commit I found when researching why the issue
didn't happen in Linux, I already found that Tegra 2 reference docs
had a different information about the register compared to Tegra 3.

I consider that a single variable is enough since the value is only
non-zero when we want to set a new address. But if is necessary i can
copy like Linux does.

Regards,
Ion Agorria

El mar, 15 oct 2024 a las 11:56, Mattijs Korpershoek
(<mkorpershoek at baylibre.com>) escribió:
>
> Hi Svyatoslav,
>
> Thank you for the patch.
>
> On dim., oct. 13, 2024 at 17:58, Svyatoslav Ryhel <clamor95 at gmail.com> wrote:
>
> > From: Ion Agorria <ion at agorria.com>
> >
> > In the older USB controllers like for example in ChipIdea controller
> > used by the Tegra 2 the "USBADRA: Device Address Advance" bitflag
> > does not exist, so the new device address set during SET_ADDRESS
> > can't be deferred by hardware, which causes the host to not recognize
> > the device and give an error.
> >
> > Instead store it until ep completes to apply the change into the hw
> > register as Linux kernel does. This should fix regression on old and
> > and be compatible with newer controllers.
>
> Since this is based on a linux commit, can we please mention the
> revision in the commit message?
>
> Per my understanding, this would be:
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ef15e5490edc7edf808d3477ab32e0e320792f65
>
> >
> > Signed-off-by: Ion Agorria <ion at agorria.com>
> > Signed-off-by: Svyatoslav Ryhel <clamor95 at gmail.com>
> > ---
> >  drivers/usb/gadget/ci_udc.c | 24 +++++++++++++++++++++++-
> >  drivers/usb/gadget/ci_udc.h |  1 +
> >  2 files changed, 24 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/usb/gadget/ci_udc.c b/drivers/usb/gadget/ci_udc.c
> > index bbe03cfff1f..4bff75da759 100644
> > --- a/drivers/usb/gadget/ci_udc.c
> > +++ b/drivers/usb/gadget/ci_udc.c
> > @@ -649,12 +649,30 @@ static void flip_ep0_direction(void)
> >       }
> >  }
> >
> > +/*
> > + * This function explicitly sets the address, without the "USBADRA" (advance)
> > + * feature, which is not supported by older versions of the controller.
> > + */
> > +static void ci_set_address(struct ci_udc *udc, u8 address)
> > +{
> > +     DBG("%s %x\n", __func__, address);
> > +     writel(address << 25, &udc->devaddr);
> > +}
> > +
> >  static void handle_ep_complete(struct ci_ep *ci_ep)
> >  {
> >       struct ept_queue_item *item, *next_td;
> >       int num, in, len, j;
> >       struct ci_req *ci_req;
> >
> > +     /* Set the device address that was previously sent by SET_ADDRESS */
> > +     if (controller.next_device_address != 0) {
> > +             struct ci_udc *udc = (struct ci_udc *)controller.ctrl->hcor;
> > +
> > +             ci_set_address(udc, controller.next_device_address);
> > +             controller.next_device_address = 0;
> > +     }
> > +
> >       num = ci_ep->desc->bEndpointAddress & USB_ENDPOINT_NUMBER_MASK;
> >       in = (ci_ep->desc->bEndpointAddress & USB_DIR_IN) != 0;
> >       item = ci_get_qtd(num, in);
> > @@ -783,7 +801,7 @@ static void handle_setup(void)
> >                * write address delayed (will take effect
> >                * after the next IN txn)
> >                */
> > -             writel((r.wValue << 25) | (1 << 24), &udc->devaddr);
> > +             controller.next_device_address = r.wValue;
> >               req->length = 0;
> >               usb_ep_queue(controller.gadget.ep0, req, 0);
> >               return;
> > @@ -814,6 +832,9 @@ static void stop_activity(void)
> >       int i, num, in;
> >       struct ept_queue_head *head;
> >       struct ci_udc *udc = (struct ci_udc *)controller.ctrl->hcor;
> > +
> > +     ci_set_address(udc, 0);
> > +
> >       writel(readl(&udc->epcomp), &udc->epcomp);
> >  #ifdef CONFIG_CI_UDC_HAS_HOSTPC
> >       writel(readl(&udc->epsetupstat), &udc->epsetupstat);
> > @@ -934,6 +955,7 @@ static int ci_pullup(struct usb_gadget *gadget, int is_on)
> >       struct ci_udc *udc = (struct ci_udc *)controller.ctrl->hcor;
> >       if (is_on) {
> >               /* RESET */
> > +             controller.next_device_address = 0;
> >               writel(USBCMD_ITC(MICRO_8FRAME) | USBCMD_RST, &udc->usbcmd);
> >               udelay(200);
> >
> > diff --git a/drivers/usb/gadget/ci_udc.h b/drivers/usb/gadget/ci_udc.h
> > index bea2f9f3fe3..807f2084c1e 100644
> > --- a/drivers/usb/gadget/ci_udc.h
> > +++ b/drivers/usb/gadget/ci_udc.h
> > @@ -105,6 +105,7 @@ struct ci_drv {
> >       struct ept_queue_head           *epts;
> >       uint8_t                         *items_mem;
> >       struct ci_ep                    ep[NUM_ENDPOINTS];
> > +     u8                              next_device_address;
>
> Comparing to
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ef15e5490edc7edf808d3477ab32e0e320792f65,
>
> Can we please keep similar logic ?
> Having both:
> - bool setaddr
> - u8 address
>
> This way, we keep the diff with the linux driver a bit lower.
>
> >  };
> >
> >  struct ept_queue_head {
> > --
> > 2.43.0