On Tue, 26 Jul 2005, Enrico wrote: > I don't know if you want/can help me but I need help with a USB driver that > I'm writing for an embedded device. > > The machine uses an host controller NEC uPD720101 and we have to interface > with the IOmega HDD usb 2.0 that mounts a NEC uPD720130. > > Our driver it's not based on linux standard but it's a very retailed version > intended to work only for mass storage devices (like pen-disks and hdd > devices). We only support bulk-only protocol. > > With many devices the driver works fine: that is, we are able to inquiry > infos, read all descriptors, read capacity and read/write sectors, but with > IOmega we can't write anything... All read commands (descriptors, capacity, > mode_sense(6) and read_sector(10)) work as we expect and don't return any > error, but when we try to send data (a single sector with write sector or > using mode_select) to the IOmega HDD we have an error. > The error is a bulk in and/or bulk out stall (in CSW_STATUS) during the very > first write. > > We have implemented the function for stall recovery (reset_recovery) but same > result. > > It is possible that the device is _write protected_ in some ways? (obviously > in the user guide of the device nothing it's mentioned about this > possibility) > If we plug the device into a normal pc with Linux on board all work perfectly > and so we are wondering if there is some kind of command (UFI or Control) > that enables write. > > We tried to contact NEC and IOmega to obtain some infos but it seems that we > speak an alien language talking about "descriptors", "qtd" and "UFI" and so > we try this way hoping in better luck :)
On the Linux PC, you can try turning on CONFIG_USB_STORAGE_DEBUG or using usbmon to see what packets are being transferred. Compare that with the packets being sent by your custom driver and look for differences. The Linux driver doesn't include any special commands to enable writes. Alan Stern ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
