[powerstation-owners] New experimental Firmware

[Stefan Nürnberger]

Adrian Reber wrote:
> On Tue, Nov 25, 2008 at 03:15:42PM +0100, Stefan Nürnberger wrote:
>> I tried following kernel versions:
>> - vanilla 2.6.27.4
>> - vanilla 2.6.27.7
>> - 2.6.24-r3 (gentoo patchset)
>>
>> All exhibit the same behaviour. The system freezes without any console 
>> output, seconds after the usb disk is detected. The firmware recognizes 
>> the disk while scanning the usb ports, if it is switched on prior to 
>> boot. In this case linux will lock up during the boot process 
>> (presumably when the device is detected).
> 
> To be honest I am surprised that the firmware detects the devices.

I was surprised, too. It looks like it could be possible to boot from 
usb, even though it was said the firmware doesn't support that (but I 
didn't try that).

> 
>> With 2.6.24 the system does not freeze immediately but about 20 seconds 
>> after the device is detected. Output from 'dmesg' shows that the device 
>> is detected normally. But the special device file (/dev/sdb*) seems not 
>> to be created or is removed shortly after. There is no output in dmesg 
>> right before the freeze except for the device detection. Especially 
>> there is nothing unusual.
>>
>> The same is true for usb sticks at the 2.0 ports.
>>
>> I now thought it could be related to my linux installation. Something 
>> with udev or similar. So I tried to mount the device with the gentoo 
>> minimal install cd for powerstation. The device is recognized and device 
>> files /dev/sdb* are created but when I try to mount it, the machine 
>> still freezes. Maybe this is a firmware bug, after all.
> 
> My first thought is that it is probably not a firmware bug. Because the
> firmware is gone at that point and Linux is the only thing running and
> touching the devices.

Yes, this is what I thought, too. I should try a bunch of LiveCDs to 
confirm the problem. Unfortunately there are not many of them out there 
that will boot on the powerstation. A YDL LiveCD would be neat for 
testing ;)

> 
>> I have no time for further tests right now. Anyway, If you have some 
>> idea what could cause this or how to further debug, please let me know.
> 
> What happens if you boot to the firmware prompt and turn then the devices
> on? Does it still crash in Linux? It could be that the firmware does not
> correctly disable the controller before booting Linux and there is still
> some DMA transaction active.

I tried that. I booted to firmware prompt and switched the usb harddisk 
on. The firmware did not detect it, since the "Scan USB" part was 
already done. The effect in Linux is still the same:

With kernel 2.6.27.x:
- system will hang during boot when device is connected/switched on.
- system will boot fine if device is switched off during boot.
- system hangs as soon as the device is switched on.
- no output in dmesg, not even "device detected"

With kernel 2.6.24-gentoo-r3:
- system will boot fine whether device is switched on or off
- system hangs seconds after the first attempt to do something with the 
device, e.g. trying to mount the device or even a simple 'lsusb'
- normal "device detected" output in dmesg

> 
> Could you somehow get me the output of the serial console with the
> devices enabled? I am not sure it will help but maybe I can detect
> something odd.
> 

I attached two boot logs (including firmware and linux boot).
powerstation_usbstorage_boot.txt - with the usb harddisk switched on 
prior to boot. Booting kernel 2.6.27.7 -> freezes during boot

powerstation_usbstorage_boot2.txt - with usb harddisk switched on while 
in SLOF boot menu. Booting kernel 2.6.24-gentoo-r3 -> freezes after 'lsusb'

There are some characters missing in the output sometimes. I believe 
this is caused by the (very long) nullmodem cable I used. Output looks 
fine with my serial terminal which is connected through a way shorter cable.

Stefan


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