Hi,
Peter Chen <hzpeterchen@xxxxxxxxx> writes:
>> Peter Chen <peter.chen@xxxxxxx> writes:
>> > For isoc endpoint descriptor, the wMaxPacketSize is not real max packet
>> > size (see Table 9-13. Standard Endpoint Descriptor, USB 2.0 specifcation),
>> > it may contain the number of packet, so the real max packet should be
>> > ep->desc->wMaxPacketSize && 0x7ff.
>> >
>> > Cc: Felipe F. Tonello <eu@xxxxxxxxxxxxxxxxx>
>> > Cc: Felipe Balbi <felipe.balbi@xxxxxxxxxxxxxxx>
>> > Fixes: 16b114a6d797 ("usb: gadget: fix usb_ep_align_maybe
>> > endianness and new usb_ep_aligna")
>> >
>> > Signed-off-by: Peter Chen <peter.chen@xxxxxxx>
>> > ---
>> > include/linux/usb/gadget.h | 5 ++++-
>> > 1 file changed, 4 insertions(+), 1 deletion(-)
>> >
>> > diff --git a/include/linux/usb/gadget.h b/include/linux/usb/gadget.h
>> > index 8e81f9e..cce2db6 100644
>> > --- a/include/linux/usb/gadget.h
>> > +++ b/include/linux/usb/gadget.h
>> > @@ -429,7 +429,10 @@ static inline struct usb_gadget *dev_to_usb_gadget(struct device *dev)
>> > */
>> > static inline size_t usb_ep_align(struct usb_ep *ep, size_t len)
>> > {
>> > - return round_up(len, (size_t)le16_to_cpu(ep->desc->wMaxPacketSize));
>> > + int max_packet_size = (size_t)le16_to_cpu(ep->desc->wMaxPacketSize)
>> > + && 0x7ff;
^^
hehe, I just noticed this bug. Did you really test this patch? :-)
>> > +
>> > + return round_up(len, max_packet_size);
>> > }
>>
>> care to update this to use new usb_endpoint_maxp()?
>>
>
> But it is a bug existed at v4.9, the usb_ep_align returns wrong request
> length for isoc. I found this bug by running usbtest.
keep your & (after fixing it), but use usb_endpoint_maxp(). Later we can
just remove the unnecessary & operation.
--
balbi
Attachment:
signature.asc
Description: PGP signature
