Screen flickering in dark areas in Ubuntu

Question

Starting with Ubuntu 10.04 I have flickering in darker areas of the screen with my HP Compaq nc6400 notebook. This happens with Ubuntu 10.04 with 32-bit as well as with 64-bit default installation (no manual X-windows configuration). Never had this problem with Ubuntu 9.04 or 9.10.

Running lspci outputs:

00:00.0 Host bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express Memory Controller Hub (rev 03)
00:01.0 PCI bridge: Intel Corporation Mobile 945GM/PM/GMS, 943/940GML and 945GT Express PCI Express Root Port (rev 03)
00:1b.0 Audio device: Intel Corporation N10/ICH 7 Family High Definition Audio Controller (rev 01)
00:1c.0 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 1 (rev 01)
00:1c.1 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 2 (rev 01)
00:1c.3 PCI bridge: Intel Corporation N10/ICH 7 Family PCI Express Port 4 (rev 01)
00:1d.0 USB Controller: Intel Corporation N10/ICH7 Family USB UHCI Controller #1 (rev 01)
00:1d.1 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #2 (rev 01)
00:1d.2 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #3 (rev 01)
00:1d.3 USB Controller: Intel Corporation N10/ICH 7 Family USB UHCI Controller #4 (rev 01)
00:1d.7 USB Controller: Intel Corporation N10/ICH 7 Family USB2 EHCI Controller (rev 01)
00:1e.0 PCI bridge: Intel Corporation 82801 Mobile PCI Bridge (rev e1)
00:1f.0 ISA bridge: Intel Corporation 82801GBM (ICH7-M) LPC Interface Bridge (rev 01)
00:1f.1 IDE interface: Intel Corporation 82801G (ICH7 Family) IDE Controller (rev 01)
00:1f.2 SATA controller: Intel Corporation 82801GBM/GHM (ICH7 Family) SATA AHCI Controller (rev 01)
01:00.0 VGA compatible controller: ATI Technologies Inc M52 [Mobility Radeon X1300]
02:06.0 CardBus bridge: Texas Instruments PCIxx12 Cardbus Controller
02:06.2 Mass storage controller: Texas Instruments 5-in-1 Multimedia Card Reader (SD/MMC/MS/MS PRO/xD)
02:06.3 SD Host controller: Texas Instruments PCIxx12 SDA Standard Compliant SD Host Controller
02:06.4 Communication controller: Texas Instruments PCIxx12 GemCore based SmartCard controller
08:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5753M Gigabit Ethernet PCI Express (rev 21)
10:00.0 Network controller: Intel Corporation PRO/Wireless 3945ABG [Golan] Network Connection (rev 02)

Maybe the most important line is

01:00.0 VGA compatible controller: ATI Technologies Inc M52 [Mobility Radeon X1300]

Answer 1

I needed to create the file /etc/modprobe.d/radeon-kms.conf, add following line

options radeon modeset=0

and had to restart. Now flickering is gone. :)

Answer 2

It may well be a driver issue. Have you tried installing a driver for this card yet? According to what I have read your exact card is no longer supported under the official driver releases from ATI. That said there is an open source alternative that seems to have worked for a good chunk of people over on the Ubuntu forums. I would post all the instructions here but there are so many steps that I will instead post some links for you:

Thread about problem with ATI 1300
Community guide for installing opensource driver
2nd Community guide for installing opensource driver.

Let us know how you get on with these or if this helps.

Answer 3

I've solved this problem. Follow the steps that I mention here:

https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-ati/+bug/665233/comments/7

Remove everything that has something to do with the graphics environment, as it says in the Ubuntu wiki page.

Then,

$ gksudo gedit /etc/default/grub

And change this line:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"

to this one:

GRUB_CMDLINE_LINUX_DEFAULT="quiet splash nomodeset acpi_backlight=vendor"

Then

$ sudo update-grub

Reboot and be happy. Desktop effects work too.

Answer 4

It seems something is wrong with the ATI 1300. I found something to do in order fix this problem:

In my case I added a command to the kernel:

radeon.new_pll=0

To do this we must to edit the file /etc/default/grub

sudo gedit /etc/default/grub

And in this line:

GRUB_CMDLINE_LINUX=""

We put the additional line command:

GRUB_CMDLINE_LINUX="radeon.new_pll=0"

And finally we must to run the command grub2 typing this in order the changes be done:

sudo update-grub2

May be you have to re-start your system.

Thanks to Geek Cesar