On Fri, 14 Jan 2011, Tanya Brokhman wrote: > Hi All, > > I was looking at do_start_stop() function in f_mass_storage.c and have a > small question regarding its implementation. > According to the SCSI spec if the LOEJ bit of the START_STOP_UNIT CBW is 1 > and so is the START bit - the medium should be loaded. I don?t see this > implemented in do_start_stop(). According to the code if START = 1 but the > lun is closed we return error. According to my understanding if START =1 > and the lun is closed and LOEJ = 1 then the lun should be reopened. > > Please advice. Think of a CDROM drive. If you send a START-STOP UNIT command with START and LOEJ both set to 1, but there is no disc in the drive, you will get an error. The drive doesn't magically put a disc into itself. That's sort of how do_start_stop() works. fsg_lun_close() is like opening the door and removing the disc from the drive. fsg_lun_open() is like putting a disc in the drive and shutting the door. START=1 won't work if there isn't a disc in the drive. 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
