Comment # 2 on bug 1046957 from Iakov Karpov

(In reply to Takashi Iwai from comment #1)
> Is it with Nvidia binary-only driver or nouveau?  You can check without the
> nvidia graphics driver but efifb whether it gives the difference.
> 
> Other than that, it's a bit tough to check without the detailed information
> about your hardware.  Basically the way to track is to either check the
> behavior change by disabling the h/w component one-by-one, or to try git
> bisection.

It's nouveau. There is no point using proprietary nvidia driver in my case,
since the nvidia gpu is not much faster than integrated intel video.

How do I disable components one-by-one?

sudo /sbin/lspci
00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family
DRAM Controller (rev 09)
00:01.0 PCI bridge: Intel Corporation Xeon E3-1200/2nd Generation Core
Processor Family PCI Express Root Port (rev 09)
00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core
Processor Family Integrated Graphics Controller (rev 09)
00:16.0 Communication controller: Intel Corporation 6 Series/C200 Series
Chipset Family MEI Controller #1 (rev 04)
00:1a.0 USB Controller: Intel Corporation 6 Series/C200 Series Chipset Family
USB Enhanced Host Controller #2 (rev 05)
00:1b.0 Audio device: Intel Corporation 6 Series/C200 Series Chipset Family
High Definition Audio Controller (rev 05)
00:1c.0 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI
Express Root Port 1 (rev b5)
00:1c.1 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI
Express Root Port 2 (rev b5)
00:1c.5 PCI bridge: Intel Corporation 6 Series/C200 Series Chipset Family PCI
Express Root Port 6 (rev b5)
00:1d.0 USB Controller: Intel Corporation 6 Series/C200 Series Chipset Family
USB Enhanced Host Controller #1 (rev 05)
00:1f.0 ISA bridge: Intel Corporation HM65 Express Chipset Family LPC
Controller (rev 05)
00:1f.2 SATA controller: Intel Corporation 6 Series/C200 Series Chipset Family
6 port SATA AHCI Controller (rev 05)
00:1f.3 SMBus: Intel Corporation 6 Series/C200 Series Chipset Family SMBus
Controller (rev 05)
01:00.0 VGA compatible controller: nVidia Corporation GF119M [GeForce GT 520M]
(rev a1)
03:00.0 Network controller: Atheros Communications Inc. AR9285 Wireless Network
Adapter (PCI-Express) (rev 01)
04:00.0 Ethernet controller: Atheros Communications AR8151 v2.0 Gigabit
Ethernet (rev c0)