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

[Mattijs Korpershoek <mkorpershoek@baylibre.com>]

On jeu., oct. 17, 2024 at 16:02, Svyatoslav Ryhel <clamor95@gmail.com> wrote:

> чт, 17 жовт. 2024 р. о 15:21 Mattijs Korpershoek
> <mkorpershoek@baylibre.com> пише:
>>
>> Hi,
>>
>> On mer., oct. 16, 2024 at 21:57, Ion Agorria <ionpl9@gmail.com> wrote:
>>
>> > 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.
>>
>> You are right, a single variable is enough. I'd still prefer to have
>> what Linux does because it will make it easier to compare with the Linux
>> driver in the future,
>>
>
> Hello!
>
> Proposed patch already does what Linux changes do. Your request to
> make it "same" as Linux is impossible to achieve since the u-boot
> driver itself does not descend from Linux, nor it is similar to Linux
> one. There is nothing to compare with Linux in the future.

I'm not saying it should be a verbatim copy of the Linux driver.
I'm saying that keeping similar variable names can help
people comparing both.

Ion just send previously:

"""
Yes that's the correct commit I found when researching why the issue
didn't happen in Linux
"""

So clearly, comparison with the linux driver is valuable given that it
was done for **this very patch**.

>
> Best regards,
> Svyatoslav R.
>
>> Thanks
>> Mattijs
>>
>> >
>> > Regards,
>> > Ion Agorria
>> >
>> > El mar, 15 oct 2024 a las 11:56, Mattijs Korpershoek
>> > (<mkorpershoek@baylibre.com>) escribió:
>> >>
>> >> Hi Svyatoslav,
>> >>
>> >> Thank you for the patch.
>> >>
>> >> On dim., oct. 13, 2024 at 17:58, Svyatoslav Ryhel <clamor95@gmail.com> wrote:
>> >>
>> >> > From: Ion Agorria <ion@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@agorria.com>
>> >> > Signed-off-by: Svyatoslav Ryhel <clamor95@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