[SOLVED] video mode changes during boot

idnotcrae · 03-29-2012, 02:32 PM

slackware boot with the penguin logo at the top and the text shows normally then the screen gets black and continue again with smaller text and the penguin logo has disappeared. this does not annoy me actualy but i just wanna find out why this happens.

I'm running slackware 13.37 and here is my graphic card type and lilo config

Quote:

root@H:/home/tux# lspci | grep -i vga
00:02.0 VGA compatible controller: Intel Corporation Mobile 915GM/GMS/910GML Express Graphics Controller (rev 03)
root@H:/home/tux# cat /etc/lilo.conf
# LILO configuration file
# generated by 'liloconfig'
#
# Start LILO global section
boot = /dev/sda
compact # faster, but won't work on all systems.
# Standard menu.
message = /boot/boot_message.txt

# Append any additional kernel parameters:
append=" vt.default_utf8=0"
#prompt
#timeout = 5
# VESA framebuffer console @ 1024x768x256
vga = 773
# Normal VGA console
#vga = normal

adamk75 · 03-29-2012, 05:37 PM

Intel GPUs now support KMS. The kernel loads a module ('i915' in this particular case) which reads the EDID from the monitor and switches the console to the monitors preferred resolution. You can force a resolution by using the video=XRESxYRES kernel option (ie. video=640x480).

Adam

idnotcrae · 03-29-2012, 06:33 PM

thank you Adam, now i understand why video resolution changes, and i tried to force a resolution and added "video=1024x768" in lilo.conf but nothing happened, is there anything else missing?

adamk75 · 03-29-2012, 06:36 PM

Did you rerun 'lilo' after editing /etc/lilo.conf? That should do it. What's the output of 'cat /proc/fb' ?

Adam

idnotcrae · 03-29-2012, 07:03 PM

no i forgot to run lilo,,, actually I always forget running it after any change of lilo.conf

,, anyway i run lilo now but here is the output

Quote:

bash-4.1# lilo
Unrecognized token "video" at or above line 12 in file '/etc/lilo.conf'
bash-4.1# cat /proc/fb
0 inteldrmfb

idnotcrae · 03-29-2012, 07:14 PM

i've noticed these lines by "dmesg" may help in this situation

Quote:

9.907341] fb: conflicting fb hw usage inteldrmfb vs VESA VGA - removing generic driver
[ 9.908320] Console: switching to colour dummy device 80x25
[ 9.911074] [drm:intel_panel_get_max_backlight] *ERROR* fixme: max PWM is zero.
[ 9.911080] Console: switching to colour frame buffer device 160x50
[ 9.916058] fb0: inteldrmfb frame buffer device

adamk75 · 03-29-2012, 07:29 PM

Well you're definitely using KMS, but you need to add the video option to the append line in /etc/lilo.conf. I think you must have added it on its own line.

Once you make that change and run 'lilo', reboot and your console resolution should be 1024x768. You can confirm this with 'fbset'.

Adam

idnotcrae · 03-29-2012, 07:54 PM

fbset at the console gives me a resolution of 1280x800

it seems i'm missing something, lilo does not accept "video=XRESxYRES" option,, may be i need to read about frame buffer, i'll google it and see if i can learn additional information about it.

adamk75 · 03-29-2012, 07:59 PM

Adding video=1024x768 to the append line definitely works here on my laptop with an intel GPU. My append line in /etc/lilo.conf looks like this now:

Code:

append=" vt.default_utf8=0 video=1024x768 "

Adam

idnotcrae · 03-29-2012, 08:14 PM

the append line works for me now and run lilo without problems with "video=XRESxYRES",,, however i still have the same problem ,,, during the boot my screen get black and then shows again without penguin logo. does that mean forcing a resolution did not work!

adamk75 · 03-29-2012, 08:23 PM

No, it means the kernel is first launching with the vesa framebuffer and then switching to the KMS provided framebuffer when the i915 kernel module loads.

idnotcrae · 03-29-2012, 08:38 PM

that's what u already told me at the beginning,,, i thought i can boot without the changing in the resolution,,and i know i've asked many questions so far

,,, thank u for ur patience

0mani · 03-29-2012, 11:06 PM

I have the same problem. Lilo will not exceed 800x600 resolution, but will switch to KMS i915 driver upon initrd initializations. I want to use KMS i915 straight from the lilo getgo. I have yet to figure it out after 2 days of tinkering.

Will building the i915 straight in to the kernel instead of as a module help? If so, how do i make sure it loads on boot?

H_TeXMeX_H · 03-30-2012, 02:07 AM

Quote:

Originally Posted by 0mani

Will building the i915 straight in to the kernel instead of as a module help? If so, how do i make sure it loads on boot?

It may fix the problem. A driver that is built-in does not need to be loaded.

adamk75 · 03-30-2012, 04:14 AM

You won't be able to get KMS working "straight from the lilo getgo." KMS is part of the linux kernel and lilo launches before the kernel. If you build KMS into the kernel, however, you can get it to load within the first few seconds of the kernel loading.

Adam