On 19/12/24(Thu) 14:18, Kirill A. Korinsky wrote:
> [...] 
> However, the situation is different for IN transfers. The kernel reads
> packets from the device, but they may be shorter than the expected size. As
> a result, the kernel tracks the total length of packets read using
> xfer->actlen and updates xfer->frlengths[i] accordingly.

Understood.  I'd prefer if we could find another solution than adding an
array to every USB transfer descriptor.
It seems to me that all isochronous USB drivers use frames of the same size,
which mean we could calculate the offset with:

	(xfer->length / xfer->nframes)

Could that work?

On a related note, is their any OS and/or driver that use isochronous
transfers with frames of different sizes?