Hi Alan, >> > It is a bug in the Titanium firmware. In the logs for both handhelds >> you >> > can see where the kernel sends a Set-Interface request after your >> driver >> releases the interface. (The kernel does this automatically so that the >> interface will be back in its original condition when the next driver binds to it.) Both devices return an error, which is a perfectly legal response. >> > >> > However the Titanium then crashes. It doesn't respond to the >> Clear-Halt >> commands sent by the kernel after the Set-Interface fails, whereas the TI84+ acknowledges them correctly. Since it has crashed, your driver is >> unable to reconnect and you have to reset the device by unplugging it. >> > >> > The source of the errors is the Titanium failure to respond to the >> kernel's Clear-Halt requests. >> I have a burning question: why Linux does not handle this behaviour while >> Windows does not reject it? > > Which behavior are you talking about? There are at least two important things going on here:
About behaviour, I was talking about the fact that Windows and Linux does not follow the same init/de-init sequence. I have taken a look at my WDM driver code. Sequence is the following: 1) open: - set device descriptor - set configuration descriptor - set interface descriptor 2) close: set configuration to NULL (if NULL, the device will be set into its unconfigured state). Because I'm curious, is Windows following USB standard by doing that? > 1. The kernel sends a Set-Interface request. I don't know why > Windows doesn't do the same thing. Ask somebody at Microsoft. > > 2. The Titanium crashes. Neither Linux nor Windows can handle > this. Once the device has crashed, all you can do is unplug it. > >> Can I handle this 'quirk' directly in my tiusb kernel module or is this behaviour managed in the USB core (and thus, not accessible from an upper >> level)? I'm not a USB-internals guru ;-) > > One thing you _can_ do is to install a firmware update, if any are The TiLP team is thinking about patching the firmware on-calc or installing a TSR to prevent this but it's an hack. > available. If that doesn't work out, you can report the problem to Texas > Instruments and ask them to issue an update to fix it. Ti Education does not care about Linux :-( > > Alan Stern > Thanks. Regards, Romain. ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys - and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
