On Tue, 16 Apr 2013, victor yeo wrote: > From the usbmon trace and driver log, i can only see that TEST UNIT > READY command is sent out but UDC driver does not receive it. May i > ask, under what circumstances, is gadget driver calling > start_transfer() to schedule reading from bulk-out endpoint ? file_storage.c calls start_transfer() whenever it expects the host to send a bulk-out packet. These times include: When the gadget is waiting for the host to send a CBW packet containing a SCSI command; When the gadget is waiting for the host to send the data part of a WRITE command. The driver also calls start_transfer() whenever it wants to send a bulk-in packet to the host: When the gadget wants to send the data part of a reply to a command such as READ or READ CAPACITY; When the gadget wants to send a CSW packet containing the status of a completed SCSI command. 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
