[lfs-support] Blank screen when booting with 3.13.3 kernel. - LFS 7.5

Ken Moffat zarniwhoop at ntlworld.com
Wed Mar 12 15:40:43 PDT 2014

On Wed, Mar 12, 2014 at 02:29:52PM -0500, rhubarbpieguy at gmail.com wrote:
> On 03/12/14 12:11, Duc Tran wrote:
> >On 03/12/2014 11:11 PM, Armin K. wrote:
> >>On 03/12/2014 05:09 PM, rhubarbpieguy at gmail.com wrote:
> >>>On 03/12/14 10:19, Merell L. Matlock, Jr. wrote:
> >>>>On 03/12/14 10:54, Armin K. wrote:
> >>>>>On 03/12/2014 03:46 PM, rhubarbpieguy at gmail.com wrote:

[ keeping all that, I've lost track of who wrote what ;-) ]

> >>Could you post your kern.log from /var/log after you boot? (you can get
> >>it from chroot after reboot iirc). Compress it before sending or it
> >>might get blocked.
> >>
> >I also had no success after deselecting Sony Vaio Programmable I/O Control Device Support.

 A couple of things I noticed, the first of which is relevant to
this, and hte second of which might make things more comfortable
when you have this issue sorted.  First:

Mar 12 13:22:40 lfs kernel: [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness
Mar 12 13:22:40 lfs kernel: [Firmware Bug]: ACPI: No _BQC method, cannot determine initial brightness

 This is supposedly fixed with "acpi_backlight=vendor" but I think you
said that didn't help.

 Later, some messages showing the console was created :
Mar 12 13:22:40 lfs kernel: fbcon: inteldrmfb (fb0) is primary device
Mar 12 13:22:40 lfs kernel: Console: switching to colour frame buffer device 160x50
Mar 12 13:22:40 lfs kernel: i915 0000:00:02.0: fb0: inteldrmfb frame buffer device

So it seems that the console is there, but without the backlight.
Does your config have all of the CONFIG_BACKLIGHT settings which you
had in 3.10 ?

Looking at one of the _many_ matches for "ACPI: No _BQC method" I
found an old one which led me to suggest that you try
i915.invert_brightness=1 in the boot args.  If that helps, you might
need to take it upstream : there seem to be a horrendous number of
variations in intel graphics chips/implementations, and breakage of
some models seems to happen from time to time.

 This option is documented in the kernel's
Documentation/kernel-parameters.txt file.

 I assume that you are putting the options in the right place, on
the same line as root= ?  I'm sure you are, but best to check.

 Iff none of this helps, it might be a kernel regression.  Ideally,
try to isolate where it happened (e.g. try 3.13.0, 3.12.0, 3.11.0
until you find one that works, and then perhaps move forward through
its stable releases to find out where it broke).  It's also possible
that this has worked sometimes, but not others, on your hardware.
*** But first try the latest 3.13 just in case it has already been
fixed ***


 I don't know what size of screen you have (inches or cm, as well as
pixels), but 160x50 might be a bit tiny to read - if so, after you
can get a display, change (or add) video=AAAAxYYYY in the boot args
where AAAA is the number of horizontal pixels on your screen, and
YYYY is the vertical.  On my old 1600x1200 4:3 screen I can also
pass 1024x768 or 800x600, but I don't know what your screen size is,
or if there are any conventional smaller sizes which would fit onto
it.  If you are trying this, copying the grub stanza for the kernel
but with something different in the menuentry such as your AAAAxYYYY
and just adding the video= will let you see it it helps and still be
able to go back to the first one.

 Using a bigger consolefont can also help - on my netbook I use a
12x22 font to make it easier to read.  That requires setting font
support, fonts, and Sun 12x22 in the kernel, and the LFS sysconfig
will need to either _not_ specify a font (i.e. use the kernel's sun
font which is ok for American), or use one of the 12x22 fonts from
kbd to get wider coverage.  NB specifying a 12x22 font in LFS on the
current kernel which probably doesn't support 12x22 will not load
the 12x22.  If you want to try 12x22, then I suggest you try it in
the kernel and look at the kernel messages before userspace drops
back to whatever font you are currently using.  Then you can decide
is 12x22 is useful for you, and either continue, and change the font
in LFS, or give it up as "too big".

das eine Mal als Tragödie, dieses Mal als Farce

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