HELP! Kernel panic when Xenarc USB is plugged in

**rgreen103** · 05-17-2005, 08:45 AM

I am getting constant kernel panics comming out of sleep mode when using the Xenarc 800tsv with the mini mac. This only happens when the Xenarcs usb is plugged into the mac mini and the mini comes out of sleep. The display is powered by the secondary 12v on the P1900. When I shut the car off the display shuts down after a few seconds then the mini goes to sleep. When I turn on the car the mini wakes after a couple of seconds then the display comes on. This is the point where I get the kernel panic. When I check the panic.log it always has the USB driver for the display as part of the trace. I have tried the drivers on the cdrom, xenarcs and the egalax website. I have also ran the Mini's hardware test with no errors. Anyone have any ideas?

Here is the setup:

Stock Mac Mini running Panther
Xenarc 800tsv
P1900 dc-dc regulator

**rgreen103** · 05-17-2005, 11:09 AM

I recreated this same type of kernel panic on my Powerbook so now I found it is not just machine specific or OS X version specific. I contacted Xenarc support and they are fowarding my log file to Egalax.

**zPilott** · 05-17-2005, 01:23 PM

you might want to see if there are any other drivers out there. For the PC there are more than a handful of websites out there, all with slightly different drivers. I downloaded the latest 2 versions on 4 or 5 websites until I found one that fixed the issues that I was having.

**DerekICT** · 05-17-2005, 05:28 PM

Might be a 800TSV issue. I have been using a 700TSV with no problems (Panther 10.3.9) for 3 weeks now.

**gommino** · 05-18-2005, 10:03 AM

Originally Posted by DerekICT

Might be a 800TSV issue. I have been using a 700TSV with no problems (Panther 10.3.9) for 3 weeks now.

I tend to agree with that, but not conclusively. Under Panther I would get a panic if I unlpugged the USB cable, but waking from sleep was OK. However sometimes the touchscreen just simply didn't work even though it was present in the System Profiler.

But under Tiger it works all the time. The only time I have got a panic is during logging out having previously unplugging the USB cable, even though that in itself did cause a panic and when I unplugged the cable I was able to plug it back in and continue using the touchscreen. However, since I don't envisage logging out whilst in the car, this won't be a problem.

Another problem I have found though is that if I leave the screen powered on when I sleep the powerbook, it will wake it up again after a few seconds, so I have to power off the screen moments before I put the powerbook to sleep, but I do get the postive side effect that when I switch on the screen the computer automatically wakes up.

Rob.

**rgreen103** · 05-18-2005, 10:44 AM

Take a look in your system.log file and see if you get a USB error each time you plug in the Xenarc USB cable. I get this on my Powerbook/Tiger and on my Mac Mini/Panther. This itself does not cause the kernel panic because I can unplug it and plug it back in without out always getting a kernel panic.

Like DerekICT was saying I am thinking it is a 800tsv issue with the current set of drivers but the Xenarc guy said that the 800tsv has the same touchscreen circuitry as the 700tsv so the same drivers should work for both. Although he did send my kernel panic log to Egalax the maker of the drivers so it looks like he may be questioning driver compatbility as well.

Do you guys know if the source code is available for OS X like it is for Linux?

The Xenarc support guy said he would contact me after he hears back from the Egalax folks but I don't have any idea how long that will take.

**gommino** · 05-18-2005, 03:46 PM

Yes, I get errors in the system log file. And just now I got the first panic from unplugging the USB cable under Tiger when checking!

I think that the problem lies with the driver...it's just buggy. Now I don't think it's dependant upon which OS or screen. However it so far seems more stable under Tiger, and the problem of the touchscreen just not working sometimes under Panther hasn't happened under Tiger. (So far, but that's what I thought about the panics!)

Rob.

**rgreen103** · 05-18-2005, 04:26 PM

Okay, It is pretty clear that it is a driver bug. I am going to see what I can get out of the debugger tonight. I can then pass this information on to Egalax and Xenarc.

**rgreen103** · 05-19-2005, 08:48 PM

I got my powerbook with osx 10.4 to kernel panic again with the xenarc usb plugged in and I debugged the kernel panic and here is what I found:

(gdb) set print asm-demangle on
(gdb) x/i 0x00005AE8
0x5ae8 <boffSCnt+1712>: .long 0x0
(gdb) x/i 0x0000000000005AE8
0x5ae8 <boffSCnt+1712>: .long 0x0
(gdb) x/i 0x000263F8-4
0x263f4 <delay_for_interval+28>: bl 0x262f4 <clock_delay_until>
(gdb) x/i 0x1B905ACC-4
0x1b905ac8 <USBTouch::ReadEEPROMThread(void*)+80>: bl 0x1b9057a4 <USBTouch::AnchorWrite(unsigned short, unsigned char*)>
(gdb) x/i 0x000A9654-4
0xa9650 <Call_continuation+16>: blrl

You can see from the above degub session that the system was in the USBTouch driver code executing AnchorWrite and ReadEEPROMThread right before the panic occurred. I wish I had the source so I could fix this.