Alan The drive do responds to MODE SENSE when plugged into Linux PC.
I used the USB analyzer and I see following commands on the wire. 1. Inquiry message - Device responds with 36 bytes of data and returns success in CSW 2. Test Unit Ready - Device returns error(0x1) in CSW 3. Request Sense - Device responds with 18 bytes of data and returns success in CSW 4. Test Unit Ready - Device Returns Success in CSW 5. Unknown Command(opcode 0x25) - Device responds with 8 bytes of data and return success in CSW. The above sequence of commands and their contents are identicle for both our embedded system and Linuc PC. The next command(given below) causes different reaction from the device on our system and PC. 6 Mode Sense(6) - on our embedded system, the device do not return ACK to data1 packet. However, On the PC, the device return the ACK to data1 packet. 7. Our embedded system repeat the Mode Sense(6) command three times and do not see the ACK from the device. The USB host driver then do reset. On the PC, the host proceeds with the Test Unit Ready command. There is gap of 12ms between the last EOP bit of ACK for CSW in command 5 above and the SYNC pattern for Mode Sense(6) command when using our system. On the other hand,the same gap is only 1-2ms on PC. The gap of 12ms is the only difference between the trace for our system and PC. Is it possible that the large gap of 12ms confuses the device ? Regards Vivek > -----Original Message----- > From: Alan Stern [mailto:[EMAIL PROTECTED] > Sent: Tuesday, September 12, 2006 12:09 PM > To: Vivek Dharmadhikari > Cc: [email protected]; Edward Qian > Subject: RE: [linux-usb-devel] 3SYSTEM's POCKET USB DISK does not work > > On Tue, 12 Sep 2006, Vivek Dharmadhikari wrote: > > > Hello Alan > > > > > The drive's firmware fails to respond to MODE SENSE commands. > > > The same thing should happen on the PC. It would be possible to > > > prevent those commands from being sent by adding an entry to the > > > blacklist table, if you want. > > > > How to add MODE_SENSE in the blacklist table ? Are you referring to > > UNUSUAL_DEV as blacklist table ? Is there a reference code > that I can > > use to add MODE_SENSE to blacklist table ? > > You're missing the point. > > Does the drive fail to respond to MODE SENSE when you plug it > into the PC? > If yes, then you know that this failure shoudn't cause a bad problem. > If no, then you know that there's something different between > the PC and the embedded Linux system. > > Alan Stern > ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
