Hi, >> Understand, UDC driver will call driver->setup(), and if the return >> value is negative, UDC driver has to set dev->protocol_stall = 1 and >> maybe call usb_ep_set_halt(). However, the hardware won't be able to >> send out zero length response. > > Don't be silly; of course it can. Nobody would be foolish enough to > design a piece of USB hardware that couldn't send a zero-length DATA > packet. > >> I think the purpose of zero length >> response is to get an ACK from the host. > > The purpose of the zero-length response is to complete the Status stage > of a control-OUT transfer. Thanks, the halt feature is ok now. The SCSI_READ_10 command has a problem. The reply value from do_read is -5, which means -EIO. The for(;;) loop in do_read() was probably broken at "if (amount_left == 0)". Is this if-statement valid? Here is the gadget log when receiving SCSI_READ_10 from Linux host. g_file_storage gadget: bulk-out, length 31: 00000000: 55 53 42 43 0f 00 00 00 00 10 00 00 80 00 0a 28 00000010: 00 00 00 00 00 00 00 08 00 00 00 00 e0 f8 02 SCSI CDB: 28 00 00 00 00 00 00 00 08 00 g_file_storage gadget: SCSI command: READ(10); Dc=10, Di=4096; Hc=10, Hi=4096 <.... driver read from SD card .....> g_file_storage gadget-lun0: file read 4096 @ 0 -> 4096 READ_10 reply -5 *** printk added by me*** g_file_storage gadget: bulk-in, length 13: 00000000: 55 53 42 53 0f 00 00 00 00 00 00 00 00 Thanks, victor -- 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
