On Sun, 9 Jan 2005, Srihari Vijayaraghavan wrote: > On Saturday 08 January 2005 14:51, Alan Stern wrote: > > ... > > I see you didn't have CONFIG_USB_STORAGE_DEBUG set when you ran this test. > > Actually I did. I do not know what log level the USB debug messages were, but > the silly syslog did not capture them. Now I have set it to write all kernel > messages.
It's a very common thing to overlook. And by the way, the log level for the debug messages is DEBUG (what a surprise!). > > Or else you didn't have your syslog daemon configured to store the > > debugging messages. If you can get anything unusual to happen with the > > debugging enabled, it would make things much easier to track down. > > That is right. I am trying to trigger the bug, and I have ensured that the > USB > debug messages are being written to the log file. But I have not triggered > the bug yet. If you're unable to trigger the bug, you can try turning the debug configuration option back off and using that patch I sent earlier. It wouldn't hurt to use that patch even with the debugging messages... > > Those errors are quite unusual. They seem to indicate there's a problem > > with your computer's USB hardware, as do the numerous spontaneous (?) > > disconnections in your log. However I'm not familiar with all the details > > of the EHCI driver. It's faintly possible that plugging the drive into a > > different USB port would work better. > > The numerous disconnections (because without debug, I can trigger the D state > process and oops within a dozen connection/disconnection, but with debug it > takes 10 times more connection/disconnection to trigger D state process, and > I do not know how many are needed for oops :-( ) are purposefully generated > to trigger the bug. Oh, so you did those by hand. All right. Probably the fact that they come fairly close together is related to the bug. I wonder if something could be causing the SCSI error handler to run when it shouldn't, using an out-of-date host structure? > Of course UHCI (USB 1) is not as fast as EHCI (USB 2). Would that not matter > for CD/DVD burning? It definitely will slow things down a lot. For normal operation you would not want to rely on it. Alan Stern ------------------------------------------------------- The SF.Net email is sponsored by: Beat the post-holiday blues Get a FREE limited edition SourceForge.net t-shirt from ThinkGeek. It's fun and FREE -- well, almost....http://www.thinkgeek.com/sfshirt _______________________________________________ linux-usb-devel@lists.sourceforge.net To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-devel
