On Mon, 1 Sep 2014, peter li wrote: > > On Sat, Aug 23, 2014 at 11:37:28PM +0800, peter li wrote: > >> 1.In which case will i get EPROTO during commuicate with usb device, i > >> called usb_bulk_msg in my usb_drv > > > > What driver is this? > > > > I write the driver based on the old version usb-skeleton.c, the driver > works fine,the error EPROTO will happen one time in about > several thousand time. > > >> 2.while i continue plug and pull the usb device a few times because of > >> EPROTO and some times (errno=110) error , the usb device is not probed, > >> nothing print in dmesg. > > > > Sounds like a broken device, is the firmware crashed in it? Does the > > device see the USB connection? > > > > the usb device is ok, i reboot the pc or move the usb device to > another pc , it works fine. No, it is not working fine. If it were working fine, you wouldn't get all these errors. > some message in dmesg: > usb 2-1:device descriptor read/64 ,error -62 > usb 2-1:new full speed USB device using ohci and address 118 > usb 2-1:can't config #1,error -71 > .... > usb 2-1:device not accpting address 119, error -71 These are all errors caused by the device. > ...... > > usb 2-1:new full speed USB device using ohci and address 118 > usb 2-1:device descriptor read/64 ,error -62 > usb 2-1:device descriptor read/64 ,error -62 > usb 2-1:new full speed USB device using ohci and address 119 > usb 2-1:device descriptor read/64 ,error -62 > usb 2-1:device descriptor read/64 ,error -62 > ....... > some times retry by pull and plug the usb device > ........ > stop probe , nothing in dmesg The device is not working correctly. 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
