Re: [gentoo-user] USB Problems

[meino.cramer@gmx.de]

john <jdm@arcticwolf.myzen.co.uk> [11-06-12 20:52]:
> On Sun, 12 Jun 2011 16:45:38 +0200
> meino.cramer@gmx.de wrote:
> 
> > john <jdm@arcticwolf.myzen.co.uk> [11-06-12 16:36]:
> > > Gents
> > > 
> > > Whenever I insert external USB device my machine locks and I have
> > > to do a hard reset (sys req does not even work). I have tried this
> > > in a graphical environment and without. Machine boots up fine with
> > > USB keyboard and mouse but will not boot up with usb storage
> > > (memory stick
> > > - tried several)
> > > 
> > > I have recently upgrade kernel to 2.6.38-r6 when this error started
> > > (approx). Hav also tried 2.6.38-r7 (which according to bugzilla
> > > should fix an issue similar to this) the error still happens.
> > > 
> > > Any suggestions on kernel config options, debugging would be
> > > appreciated. And how to trap full error message.
> > > 
> > > Error message alongs these lines 
> > > 
> > > Kernel panic not syncing - fatal exception in iterrupt
> > > ksoftirqd/1 Not tainted
> > > 
> > > 
> > > 
> > > 
> > > -- 
> > > --------------
> > > --------------
> > > John D Maunder
> > > jdm@arcticwolf.myzen.co.uk
> > > 
> > 
> > Hi John,
> > 
> > may be this could help to track th eerror more closely:
> > Recompile the kernel with CONFIG_USB_DEBUG set.
> > If not already done, enable CONFIG_MAGIC_SYSRQ and
> > read about the available commands in the according
> > docs under /usr/src/linux/Documentation/.
> > This is a overall life saver in many other cases too.
> > But it may be a security hole also -- you can disable 
> > it in /proc/ later.
> > If possible change /etc/fstab to mount the partition
> > to which logging will go with the "sync" option so
> > every log entry will go directly onto the bare metal
> > instead of a RAM buffer.
> > 
> > Reboot into console mode (no X).
> > cd to the logging directory and
> > do a tail -f onto the logfile in question
> > 
> > Insert the "USB stick of death" ;) and
> > see, whether you can see anything in the
> > tailed log.
> > 
> > If not do the magic sysrq dance to sync hds,
> > remount readonly and finally reboot.
> > 
> > Take a closer look into the resulting logs.
> > 
> > Good luck!
> > 
> > Nevertheless have a nice weekend!
> > Best regards,
> > mcc
> > 
> > 
> > 
> 
> Thanks mmc,
> CONFIG_MAGIC_SYSRQ and CONFIG_USB_DEBUG set to y
> 
> When I plug in USB device SYSREQ does not work. I have tested when
> system is normal and all ok with SYSREQ so USB device is locking up
> system completely.
> 
> I have put sync in mount table but when device is inserted error log
> is not being produced (in /var/log/messages, etc). I may end up having
> to take a photo of error log(lol). Or there maybe some other way of
> catching error which Gentoo gurus may advise.
> 
> I have tried 3 memory sticks and they all lock system up. These work
> on another PC using Arch and work on this PC dual booting with Windows.
> I have a usb hard drive which works ok so it is a memory stick only
> issue!!!!????
> 
> Hmmm. 
> 
> -- 
> --------------
> --------------
> John D Maunder
> jdm@arcticwolf.myzen.co.uk
> 

Hi John,

if sysreq does not work after inserting the usbstick then the kernel
stops working completly (the sysreq-code of the kernel is not
entered), which seems to be that something happening on very low
level (the problem not the sysreq-code of course... ;)

Just another shot into the dark:
Do you have modularized all usb-related stuff? This also may help to 
let the usb-sticks work correctly.

Ah! Another thing: Insert the related modules into
/etc/conf.d/modules so that they get loaded in a very early
phase of the bootprocess.

With modules loaded and with no usb-sticks as root inspect the
according modules with modinfo -p <modulename> to see, whether
there a additional parameters you may pass to the modules to get
an extra of informations or - better - to fix the issue.

Modify under "Kernel hacking" in the kernel config the
"Default message log level" to see more.

Furthermore there is a switch "Kernel debugging" with sub-options.
May be turning on these may also help to get closer to all evil ;)

Last thing:
If there is nothing valueable stored on the usbsticks:
Try to reformat the usbsticks. Instead of putting a FAT32-fs on the 
bare device, create a regular partition and create a Linux-fs
(reiserfs, ext2/3/4 or like that) on that partition.

This may not be good idea in general, but - if it works - this would
give a hint, where to search next.

Good luck!

Best regards,
mcc