Re: [PATCH v5] usb: Reduce 'set_address' command timeout with a new quirk

Hardik Gajjar
2023-10-25T16:40:32Z

On Wed, Oct 25, 2023 at 07:16:05PM +0300, Sergey Shtylyov wrote:
> On 10/25/23 7:00 PM, Sergey Shtylyov wrote:
>
> [...]
> > Sorry to be PITA but... (-:
>
> I just had to speak up after Alan's ACK. :-)
No problem, Thanks for the feedback. I agreed with many of them
>
> >> This patch introduces a new USB quirk, USB_QUIRK_SHORT_DEVICE_ADDR_TIMEOUT,
> >> which modifies the timeout value for the 'set_address' command. The
> >
> > This is called a request, not a command by the spec. And the USB spec
> > names the requests in all uppercase, e.g. SET_ADDRESS...
> >
> >> standard timeout for this command is 5000 ms, as recommended in the USB
> >> 3.2 specification (section 9.2.6.1).
> >
> > This section in the USB specs 1.1/2.0/3.0 talks about _all_ requests.
> > I don't have USB 3.2 but It believe it has the same wording.
> >

The patch modifies both xhci and hub.c, and the keywords 'command' come from the xhci driver.
I will change 'command' to '(all)request' and newly added 'address_device' to 'SET_ADDRESS' in hub.c.
That sounds better for hub.c

> > [...]
> >
> >> Signed-off-by: Hardik Gajjar <hgajjar@de.adit-jv.com>
> [...]
>
> >> diff --git a/drivers/usb/host/xhci.c b/drivers/usb/host/xhci.c
> >> index e1b1b64a0723..0c610a853aef 100644
> >> --- a/drivers/usb/host/xhci.c
> >> +++ b/drivers/usb/host/xhci.c
> >> @@ -3998,11 +3998,17 @@ int xhci_alloc_dev(struct usb_hcd *hcd, struct usb_device *udev)
> >> }
> >>
> >> /*
> >
> > You seem to be converting the existing comment to a kernel-doc one
> > but you miss changing from /* /** at the start and adding colons after
>
> From /* to /**, I meant to type...
>
> > the param names below...
>
> This comment update also looks like a meterial for a separate patch...
>

I think this is acceptable in the patch since it modifies the function arguments
as well. I improved the existing comments while adding information about the new
argument. However will update /* to /**

> >> - * Issue an Address Device command and optionally send a corresponding
> >> - * SetAddress request to the device.
> >> + * xhci_setup_device - issues an Address Device command to assign a unique
> >> + * USB bus address.
> >> + * @hcd USB host controller data structure.
> >> + * @udev USB dev structure representing the connected device.
> >> + * @setup Enum specifying setup mode: address only or with context.
> >> + * @timeout_ms Max wait time (ms) for the command operation to complete.
> >> + *
> >> + * Return: 0 if successful; otherwise, negative error code.
> >> */
> >> static int xhci_setup_device(struct usb_hcd *hcd, struct usb_device *udev,
> >> - enum xhci_setup_dev setup)
> >> + enum xhci_setup_dev setup, unsigned int timeout_ms)
> > [...]
>
> MBR, Sergey

Thanks,
Hardik