On Sun, 23 Jun 2013, Ming Lei wrote: > >> Since you mentioned it doesn't make sense to generate short packet > >> in the middle of transfer, also it may not be what the driver/device expected, > >> I suggest to add a check in usb_submit_urb() for this case and returns > >> failure on it simply, because all HCDs shouldn't support this sort of thing. > >> The check in usb_submit_urb() can avoid unnecessary change in HCD. > >> > >> Any comments on the idea? > > > > Wireless USB has some strange features, one of which is that the > > maxpacket sizes for endpoints can be changed. I'm afraid that adding > > this check in usb_submit_urb() would not work right for wireless USB. > > See > > > > http://marc.info/?l=linux-usb&m=136934531624850&w=2 > > From the Thomas's last reply in the discussion, looks the device's maxp > need to be set as one value which is divided evenly into 4k, so looks the > check might be OK for wireless USB too. Maybe. Thomas should be able to tell us. > > That's why, if the check is checked, I feel it should be added to each > > HCD driver separately. Maybe I'm wrong. But before doing anything, > > you should check with Thomas Pugliese. He recently added SG support to > > the wireless USB driver. > > Suppose wireless USB is one exception, it should the only one, so we can > rule it out easily by using hcd->wireless, right? Yes, that's true. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
