Re: [PATCH v2] usbcore: Add quirk for 255-bytes initial config read

[Nikhil Solanke]

On Sun, 28 Jun 2026 at 19:25, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote:
>
> On Sun, Jun 28, 2026 at 11:53:09AM +0530, Nikhil Solanke wrote:
> > I need some help with the USB_QUIRK_DELAY_INIT part. I can't figure
> > out how to make it properly work with my patch because of the
> > following reasons:
> >
> > 1. I don't want to move it to the top because, from my pov, there must
> > have been some reason for placing that quirk where it is now. so i
> > don't want to mess with it.
> >
> > 2. Regarding my idea of adding a condition — so that it doesn't change
> > the behavior when the quirk isn't set — if the full configuration set
> > exceeds 255 bytes, we would have to issue a 2nd request. In this case
> > the existing behavior would be more justified.
> >
> > So, I'm a bit confused about how to implement this properly. Adding
> > yet another condition to fix the second case doesn't feel right to me.
> > It would look unnecessarily complicated. I would appreciate a bit of
> > help and advice.
>
> If the 255-byte quirk flag isn't set, do the delay before the second
> transfer just as it is now.
>
> If the 255-byte quirk flag is set, do the delay before the first
> transfer.  If a second transfer is needed, you can do a second delay
> before it or not -- I suspect it doesn't matter.  If you want to be
> safe, add the second delay.
>
> Alan Stern

Ok thanks! Just to make sure, because the change I will introduce
won't affect any existing behavior, these changes (relating to
DELAY_INIT quirk) won't belong in a new patch, right?

Thanks,
Nikhil Solanke