6.0 and console on ThinkPad x220

nacho Lariguet lariguet at gmail.com
Thu May 20 12:42:21 PDT 2021

On Thu, 20 May 2021 11:54:29 -0700
Chuck Musser <cmusser at sonic.net> wrote:

> That's correct: if the i915 module isn't loaded, then the console works
> normally. I tried loading the driver by hand after booting and the
> console becomes frozen: nothing new is displayed. But, yes, the system
> is still running. I've always been able to SSH when the console is
> frozen. The console does take input: I tried typing the shutdown command
> as you suggested and the system did respond by shutting down cleanly. 
> I turned on the debug messages and it produced a ton of output. Nothing
> stood out to me, other than the error I mentioned earlier. I don't know
> what to look for really. But the error was this: 
> error: [drm:pid886:gen6_gmch_probe] *ERROR* Can't set DMA
> mask/consistent mask (-5) 
> Another thing to mention is that I've had kernel.kms_console=1 in
> loader.conf. I got that from an example but don't actually know what it
> means. Generally, I'm wondering where to find documentation on settings
> like that, and maybe find out about related ones. 


     kern.kms_console      Setting this tunable to 0 disables experimental
                           framebuffer support in conjunction with the i915(4)
                           or radeon(4) drivers.  It is 1 by default.

     kern.kms_columns      The number of columns to use in conjunction with
                           the i915(4) and radeon(4) drivers.  The font size
                           is scaled to match the requested number of columns.
                           This requires kern.kms_console to be set to 1.  By
                           default, syscons tries to find a more or less
                           pleasant looking default.  Setting kern.kms_columns
                           to a negative value turns off scaling.  Please note
                           that ttyv0 is restricted to 160 columns and any
                           setting of kern.kms_columns resulting in a higher
                           number of columns will be ignored for ttyv0, but
                           applied to other virtual terminals.

> Chuck 
> On 2021-05-20 03:26, karu.pruun wrote:
> > So I am I right to think that you can get the console fine but loading
> > i915 gives a frozen screen? 
> > 
> > To test this is true, remove automatic
> > loading of i915 from /etc/rc.conf and see if you get to the login
> > prompt. Then try manually loading i915 on console, as root do 'kldload
> > i915'. You can get more debug messages by setting 'drm.debug=0x777' in
> > /boot/loader.conf.
> > 
> > It will be a lot of debug output but might help diagnose the issue.
> > 
> > Question: when the screen freezes after kldloading i915, can you still
> > ssh into the machine? Can you do 'shutdown -r now' by typing on the
> > console?
> > 
> > Best  

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