# [SOLVED] Display Blinking

## Matias Jose Seco

Hello,

actually i've finisched installing an i686 Gentoo with Kernel 3.2.1-r2.

Problem: after finishing booting, the display switch off and on every 5 seconds.

Analysis: 

- it just use console (non xorg installed)

- it uses fbcon module (radeonfb)

- on Kernel i've selected no fb, because i've enabled KMS under radeon driver

- i've enabled some options that try to look at display power usage and backlight controlling

Here i attach dmesg output:

http://pastebin.com/ULWDVAVw

Actions:

- I've tried offloading radeon and fbcon module but "they're in use", i've not tried forcing

- I've found some issues upon /dev/sdb1 swap, it could trigger display blinking?

Salut,

MatiasLast edited by Matias Jose Seco on Sun Feb 26, 2012 4:29 pm; edited 2 times in total

----------

## Hu

Swap device problems should not cause this.  However, you must enable the framebuffer console if you want to use a text console when KMS is active.

----------

## shrike

Matias Jose Seco,

Hello.

I see several issues in DMESG but need more information. I will assume that you used a linux boot CD to start Gentoo install process. If you were to boot using that CD now, then the display will work correctly, yes? Entering the BIOS setup would demonstrate that the display is ok (or not) also.

I would imagine that it was difficult to provide DMESG on pastebin with a blinking display. Or do you connect with SSH/TELNET? My thought is that it is best to fix the 'blinking display' from your now bootable i686 machine rather than chroot into it via a boot CD. But working with a 'blinking display' may be more trouble than chroot.

My guess for solving the 'blinking display' problem: In the kernel config DRM (Direct Rendering Manager) and agpgart (/dev/agpgart) are selected. I use neither of these on my NoX box. Instead, I use:

```

                                                                                                                                      

                                            --- Support for frame buffer devices 

                                            [*]   Enable firmware EDID 

                                            [ ]   Framebuffer foreign endianness support  --->

                                            [*]   Enable Video Mode Handling Helpers

                                            [ ]   Enable Tile Blitting Support 

                                                  *** Frame buffer hardware drivers ***

                                            < >   Cirrus Logic support 

                                            < >   Permedia2 support  

                                            < >   CyberPro 2000/2010/5000 support

                                            < >   Arc Monochrome LCD board support

                                            [ ]   Asiliant (Chips) 69000 display support

                                            [ ]   IMS Twin Turbo display support 

                                            < >   VGA 16-color graphics support

                                            < >   Userspace VESA VGA graphics support

                                            [*]   VESA VGA graphics support

                                            < >   N411 Apollo/Hecuba devkit support

                                            < >   Hercules mono graphics support

                                            < >   Epson S1D13XXX framebuffer support

                                            < >   nVidia Framebuffer Support

                                            < >   nVidia Riva support

                                            < >   Intel LE80578 (Vermilion) support

                                            < >   Matrox acceleration

                                            < >   ATI Radeon display support

                                            < >   ATI Rage128 display support

                                            < >   ATI Mach64 display support

                                            < >   S3 Trio/Virge support

                                            < >   S3 Savage support

                                            < >   SiS/XGI display support

                                            < >   VIA UniChrome (Pro) and Chrome9 display support

                                            < >   NeoMagic display support

                                            < >   IMG Kyro support

                                            < >   3Dfx Banshee/Voodoo3/Voodoo5 display support

                                            < >   3Dfx Voodoo Graphics (sst1) support

                                            < >   VIA VT8623 support

                                            < >   Trident/CyberXXX/CyberBlade support

```

But in my case I SSH into that box. Your needs may be different. DRM, agpgart, and, Support for frame buffer devices are all located in Device Drivers/ Graphics support/. The kernel will have to be re-compiled for any changes to take effect.

VESA is a console FB that is supported by most graphics cards, PCI, AGP, or PCI-E.

Congratulations on reaching this point (a bootable machine). I think you are close to a stable machine.

Regards,

shrike

----------

## Matias Jose Seco

 *Hu wrote:*   

> , you must enable the framebuffer console if you want to use a text console when KMS is active.

 

Do you mean the option under:

-> Device Drivers

 -> Grapghics Support

  -> Console display driver

   - Framebuffer console Console support?

It's enabled (as a Module)

 *shrike wrote:*   

> If you were to boot using that CD now, then the display will work correctly, yes?

 

Yes

 *shrike wrote:*   

> Entering the BIOS setup would demonstrate that the display is ok (or not) also. 

 

Working correctly

 *shrike wrote:*   

> I would imagine that it was difficult to provide DMESG on pastebin with a blinking display. Or do you connect with SSH/TELNET? 

 

I've copied it in a USB key and done the remaining things through a laptop

 *shrike wrote:*   

> My guess for solving the 'blinking display' problem: [...] 

 

I'll need Radeon + KMS because i'll need to use Xorg only for rdesktop and a browser (and unprobably other things)

The way i use the box is directly (keyboard, mouse, display,...)

Framebuffer: on this procedure Kernel Mode Setting; i've found that any additional framebuffer should be setted, so i've selected

only Radeon + KMS

 *shrike wrote:*   

> The kernel will have to be re-compiled for any changes to take effect.

 

I've tried recompiling without display regulation options under graphics but i cant understand if i've done well recompiling:

```
#cd /usr/src/linux

#make menuconfig

[chosen/removen all needed options]

#make && make modules_install && make firmware_install (this last one to compile some firmware to use them as Modules)

[compilation]

#cp arch/i386/boot/bzImage /boot/kernel-3.2.1-gentoo-r2-linux-B (the old one is -A)

#nano -w /boot/grub/grub.conf

- kernel /boot/kernel-3.2.1-gentoo-r2-linux-A root=/dev/sda1

+ kernel /boot/kernel-3.2.1-gentoo-r2-linux-B root=/dev/sda1

```

The issue remains:

1) did i recompiled properly?

2) how can i watch kernel-3.2.1-gentoo-r2-linux-B?

3) how can i compare kernel B with kernel A?

Notes: when i go to "make menuconfig" it loads me the same options of Kernel A and not the updated options of Kernel B ->

Did i had to change something before compiling with new options? (i've saved the .config file  :Wink:  )

What do you think?

Thanks,

Matias

EDIT: The Kenerls A e B have the exact same size (in kilobytes,blocks,...) so i surely made wrong something,

i suspect that i should modify something before recompiling..

----------

## Matias Jose Seco

 *Matias Jose Seco wrote:*   

> I've tried recompiling without display regulation options under graphics but i cant understand [...] 

 

I didn't set the new options as the official .config, so i've cleaned and recompile succesfully

But the issue remains......

I think i'll try looking at some acpi options that could be badly regulating things, nevertheless i'll also try another configuration without radeon DRI

to understand if it is giving problems, as long as i see over lsmod that it has "backlight" module.....

EDIT: Should i do "env-update" every time i chroot from CD? i always do "source etc/profile" but env-update as i red, it creates environment variables, so shouldn't be necessary, true?

----------

## Hu

I would compile the framebuffer as a built-in, rather than as a module.  If you have not already, you should also enable FB_RADEON=y.  Also, I see in your dmesg that there are problems with the EDID on at least one of your output devices.  This may or may not be a problem here, but it is bad in principle.

That recompilation procedure looks fine, aside from being run as root.  This works, but is bad practice.  If you do not see your changes when you re-run make menuconfig, something is wrong.  Please post your .config to a pastebin.

----------

## shrike

Matias Jose Seco,

The steps for compiling the kernel and editing grub.conf look correct.. but it is odd that the kernel size remains the same. Pls check that you have a link in /usr/src/. For example, this link is to kernel-3.1.6:

```

x2 2012-01-25 # ls -l /usr/src/     

total 56

drwxr-xr-x  4 root root 4096 Feb 18 10:07 initramfs

lrwxrwxrwx  1 root root   18 Jan  3 16:30 linux -> linux-3.1.6-gentoo

drwxr-xr-x 20 root root 4096 Jan  8  2010 linux-2.6.28-gentoo-r5

drwxr-xr-x 20 root root 4096 Jan  8  2010 linux-2.6.29-gentoo-r3

drwxr-xr-x  3 root root 4096 Jan 27  2010 linux-2.6.30-gentoo-r4

drwxr-xr-x 20 root root 4096 Jan 27  2010 linux-2.6.32-gentoo-r1

drwxr-xr-x 20 root root 4096 Jan 14  2011 linux-2.6.32-gentoo-r3

drwxr-xr-x 20 root root 4096 Jan 14  2011 linux-2.6.32-gentoo-r5

drwxr-xr-x 20 root root 4096 Nov 18 15:56 linux-2.6.37-ck

drwxr-xr-x 24 root root 4096 Jan  3 16:29 linux-2.6.37-gentoo

drwxr-xr-x 24 root root 4096 Feb 24 17:00 linux-3.1.6-gentoo

drwxr-xr-x 23 root root 4096 Jan 13 14:24 linux-3.2.0-gentoo-r1

drwxr-xr-x 23 root root 4096 Jan 15 11:39 linux-3.2.1-gentoo

drwxr-xr-x 23 root root 4096 Jan 29 10:18 linux-3.2.1-gentoo-r2

drwxr-xr-x 23 root root 4096 Feb 21 11:18 linux-3.2.6-gentoo

```

shrike

----------

## Matias Jose Seco

 *Hu wrote:*   

> I would compile the framebuffer as a built-in, rather than as a module. If you have not already, you should also enable FB_RADEON=y. 

 

I've recompiled kernel with radeonfb and radeon dri without kms, and now is working well but with low resolution (i'll try higher ones).

I've compiled readeonfb as a Module and it dont gives problems.

So now blinking is fixed, and if, when i will start x, and radeon dri will handle display again, triggering blinking, i'll reopen this issue  :Wink: 

 *Hu wrote:*   

> Also, I see in your dmesg that there are problems with the EDID on at least one of your output devices.

 

I don't know if the following could be the reason, but over KMS description is warned that:

"When kernel modesetting is enabled the IOCTL of radeon/drm driver are considered as invalid and an error message is printed in the log and they return failure"

Now, with readeonfb, the dmesg error doesn't appear any more.

(Curiosity: descriptions says that KMS takes advantage of GPU buffer: does radeonfb do the same?)

 *Hu wrote:*   

> That recompilation procedure looks fine, aside from being run as root. This works, but is bad practice. If you do not see your changes when you re-run make menuconfig, something is wrong. Please post your .config to a pastebin.

 

 *shrike wrote:*   

> The steps for compiling the kernel and editing grub.conf look correct.. but it is odd that the kernel size remains the same. Pls check that you have a link in /usr/src/. For example, this link is to kernel-3.1.6: [...]

 

Sorry, i've explained bad:

the recompilation was already resolved: what i've mistaken is saving configurations upon "foo.config" and not ".config": so i've resolved with

```
mv foo.config .config
```

moreover, i had to perform

```
make clean

make mrproper
```

to recompile builtin options; The issue that remained (before compiling with radeonfb) was the blinking display  :Very Happy: 

Regards

----------

## Hu

 *Matias Jose Seco wrote:*   

> I've recompiled kernel with radeonfb and radeon dri without kms, and now is working well but with low resolution (i'll try higher ones).

 I strongly recommend enabling KMS.  You will need it eventually, so it would be beneficial to get it working now.

 *Matias Jose Seco wrote:*   

> I don't know if the following could be the reason, but over KMS description is warned that:
> 
> "When kernel modesetting is enabled the IOCTL of radeon/drm driver are considered as invalid and an error message is printed in the log and they return failure"

 No, that is not the reason.  That warning is advising you that you cannot use legacy UMS-based rendering when KMS is active.

----------

