Re: [PATCH v5 2/3] media: uvcvideo: add UVC_QUIRK_CTRL_THROTTLE for fragile firmware

Michal Pecio
2026-04-10T04:47:22Z

On Thu, 9 Apr 2026 17:24:36 -0700, Jeffrey Hein wrote:
> So wBytesPerInterval (8) is indeed 8x smaller than wMaxPacketSize
> (64), matching what you saw in the third-party listing.

Technically it's a spec violation if a device claims 8 bytes but
respons with a single packet larger than that to a 16 byte (or any
other) URB. Though no problems were known to result until last month.
It seems most host controllers ignore byte per interval on interrupt.

> Note that lsusb -vv does not decode wBytesPerInterval for this
> endpoint -- the value above was parsed from the raw descriptor bytes
> in sysfs. The full lsusb -vv (934 lines) is now in the repo:

It does decode it, but you need the latest usbutils version 019.

And there should be no need for lsusb -vv, just lsusb -v.
I think the output pasted into v6 patch was truncated.

Regards,
Michal