Hello altogether, [Please cc me as I am not subscribed]
here are some interesting (not to say annoying) observations regarding the usb->serial converter driver ftdi_sio. On vanilla kernels 2.6.7 and 2.6.8-rc3 I connected the device in question to the pc the first time after reboot and got this: # lsusb Bus 002 Device 001: ID 0000:0000 Bus 001 Device 002: ID 0403:6001 Future Technology Devices International, Ltd 8-bit FIFO Bus 001 Device 001: ID 0000:0000 # A disconnect seems to be handled correctly as those messages on the console indicate: # usb 1-1: USB disconnect, address 2 FTDI FT232BM Compatible ttyUSB0: FTDI FT232BM Compatible converter now disconnected from ttyUSB0 ftdi_sio 1-1:1.0: device disconnected But a reconnection is not registered under any circumstances. Neither messages on the console at reconnect time nor lsusb afterwards indicate that hotplug (or who ever) is aware of the reconnected ftdi controller. As mentioned above, this was experienced on linux 2.6.7 and 2.6.8-rc3. In contrary, on linux 2.6.5 several reconnections seem to be handled properly. Then, after reboot and the first connection on a 2.6.7 kernel, I tried to actually use the device. Just for reference: I am talking about a braille terminal which gives me as a blind person access to the contents of the computer screen. The braille terminal is equipped with a serial port and a built in ftdi serial->usb controller (the one I am talking about all the time) so you can connect it to the pc through a serial or a usb port on your option. As shown above, the ftdi controller was recognized correctly (first connection after reboot) and I tried to start the screen reader which was configured to communicate with the braille terminal through ttyUSB0. The braille terminal responsed and seemed to work properly but since the following error message was repeatedly output in a short period of time, there was not much interesting to see on the braille terminal: Aug 4 19:58:58 linux kernel: drivers/usb/serial/ftdi_sio.c: write request of 0 bytes On the 2.6.8-rc3 kernel the same messages occured but the braille terminal did not even respond to the screen reader so it was even worse. Fortunately I have got an external pl2303 usb->serial converter. Connecting this one to the serial port of the braille terminal and then the whole setup to the usb port of the computer, everything worked just fine (on 2.6.7 and 2.6.8-rc3). Nevertheless I naturally would like to make use of the internal ftdi. Please tell me what I can do to fix the problem or to do further testing to provide you with appropriate information. Is there, i.e., any reason for trying a current 2.4 kernel? A 2.4.23 I still have on my system didn't work either but showed a behaviour rather similar to the 2.6.5. The kernel did not produce any error messages but the screen reader could not open ttyUSB0 on those kernels. Thank you very much and best regards, Elias ------------------------------------------------------- This SF.Net email is sponsored by OSTG. Have you noticed the changes on Linux.com, ITManagersJournal and NewsForge in the past few weeks? Now, one more big change to announce. We are now OSTG- Open Source Technology Group. Come see the changes on the new OSTG site. www.ostg.com _______________________________________________ [EMAIL PROTECTED] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
