No console output with NETDEV_BACKEND set!

No console output with NETDEV_BACKEND set!

[Tobias Hunger]

[-- Attachment #1: Type: text/plain, Size: 1115 bytes --]

Hi!

I have finally found the time for some more experiments with the console 
problem I described here earlier (Kernel crash thread starting last Tuesday).

After disabling all possible console drivers the kernel did no longer crash, 
but I do not receive any output on my console anymore. Today I started with a 
xenU kernel configuration (which works fine!) and kept adding options to that 
till the console output disappeared. 

The first step was to enable XEN_PHYSDEV_ACCESS: everything works fine (I have 
modified xen's Kconfig.drivers to not include more on files when the flag is 
set).
 
Enabling XEN_NETDEV_BACKEND in addition to that causes the screen to stay 
blank: no more output on my console.

Any ideas how to get back my console output? Thanks!

I will keep you updated on any new things I find out...

-- 
Gruss,
Tobias

------------------------------------------------------------
Tobias Hunger           The box said: 'Windows 95 or better'
tobias@aquazul.com                     So I installed Linux.
------------------------------------------------------------

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

RE: No console output with NETDEV_BACKEND set!

[Ian Pratt]

 
> The first step was to enable XEN_PHYSDEV_ACCESS: everything 
> works fine (I have 
> modified xen's Kconfig.drivers to not include more on files 
> when the flag is 
> set).
>  
> Enabling XEN_NETDEV_BACKEND in addition to that causes the 
> screen to stay 
> blank: no more output on my console.
> 
> Any ideas how to get back my console output? Thanks!
> 
> I will keep you updated on any new things I find out...

Bizzare. Are you 100% sure about this? 

Hmm, I wander if it's xend getting confused rather than the kernel...

Ian


-------------------------------------------------------
This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting
Tool for open source databases. Create drag-&-drop reports. Save time
by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc.
Download a FREE copy at http://www.intelliview.com/go/osdn_nl

Re: No console output with NETDEV_BACKEND set!

[Tobias Hunger]

[-- Attachment #1: Type: text/plain, Size: 899 bytes --]

Hello again!

I checked some more and I think that the console is giving output, but the 
kernel got stuck:-)

I do get some text on the console. So far I had assumed that this is printed 
by Xen's domain setup tools, but it is actually printed by the guest kernel 
already. So far I never had to bother with those very first lines of the 
kernel, so please bear with my ignorance:-)

The last line I get is the one about "Kernel command line:".

It never gets to "Initializing CPU#0" that I see when running a xenU kernel 
without netbackend. I think I will add some printk's into the kernel init 
code now...

-- 
Gruss,
Tobias

------------------------------------------------------------
Tobias Hunger           The box said: 'Windows 95 or better'
tobias@aquazul.com                     So I installed Linux.
------------------------------------------------------------

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: No console output with NETDEV_BACKEND set!

[Tobias Hunger]

[-- Attachment #1: Type: text/plain, Size: 459 bytes --]

I added lots of printk's to the kernel's init code and guess what: Suddenly 
the kernel works! I get console output as expected, all is well. I really 
wonder what went wrong before!

-- 
Gruss,
Tobias

------------------------------------------------------------
Tobias Hunger           The box said: 'Windows 95 or better'
tobias@aquazul.com                     So I installed Linux.
------------------------------------------------------------

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]

Re: No console output with NETDEV_BACKEND set!

[Jan Kundrát]

Tobias Hunger wrote:
> I added lots of printk's to the kernel's init code and guess what: Suddenly 
> the kernel works! I get console output as expected, all is well. I really 
> wonder what went wrong before!
> 

And does it work after removing it ;-) ?

-jkt

-- 
cd /local/pub && more beer > /dev/mouth



-------------------------------------------------------
This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting
Tool for open source databases. Create drag-&-drop reports. Save time
by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc.
Download a FREE copy at http://www.intelliview.com/go/osdn_nl

RE: No console output with NETDEV_BACKEND set!

[Ian Pratt]

> Tobias Hunger wrote:
> > I added lots of printk's to the kernel's init code and 
> guess what: Suddenly 
> > the kernel works! I get console output as expected, all is 
> well. I really 
> > wonder what went wrong before! 
> 
> And does it work after removing it ;-) ?

Yep, it would certainly be good to get to the bottom of this. Does the position of the printk's matter, or is it the amount of text that's printed (suggesting a timing bug)?

Ian


-------------------------------------------------------
This SF.Net email is sponsored by: IntelliVIEW -- Interactive Reporting
Tool for open source databases. Create drag-&-drop reports. Save time
by over 75%! Publish reports on the web. Export to DOC, XLS, RTF, etc.
Download a FREE copy at http://www.intelliview.com/go/osdn_nl

Re: No console output with NETDEV_BACKEND set!

[Tobias Hunger]

[-- Attachment #1: Type: text/plain, Size: 615 bytes --]

On Sunday 23 January 2005 22:04, Ian Pratt wrote:
> > And does it work after removing it ;-) ?

Nope.

> Yep, it would certainly be good to get to the bottom of this. Does the
> position of the printk's matter, or is it the amount of text that's printed
> (suggesting a timing bug)?

I will check this weekend when I get back home.

-- 
Gruss,
Tobias

------------------------------------------------------------
Tobias Hunger           The box said: 'Windows 95 or better'
tobias@aquazul.com                     So I installed Linux.
------------------------------------------------------------

[-- Attachment #2: Type: application/pgp-signature, Size: 189 bytes --]