[Mageia-dev] Mageia support for GMA 3600 (Cedar Trail Atom)

Sun Apr 1 01:36:16 CEST 2012

On Sun, 11 Mar 2012 tux99-mga at uridium.org wrote:
+>
+> On Fri, 9 Mar 2012 tux99-mga at uridium.org wrote:
+> 
+> > On Fri, 9 Mar 2012, Thomas Backlund wrote:
+> > 
+> > > tux99-mga at uridium.org skrev 8.3.2012 02:18:
+> > > >
+> > > > Hi,
+> > > > I just tried Mageia 2 beta 1 on a Intel DN2800MT board hoping that it
+> > > > would have framebuffer support for the GMA 3600, but the attached
+> > > > monitor goes into standby (no signal) as soon as the frame buffer gets
+> > > > activated during boot.
+> > > >
+> > > > As far as I understand there is frame buffer support in the 3.3 kernel
+> > > > for the GMA 3600 so in theory it should work.
+> > > >
+> > > > Are you aware of this issue or should I do a bug report?
+> > > 
+> > > Yes.
+> > > 
+> > > There is a bug with Cedar Trail that got fixed upstream a few days after
+> > > 3.3-rc6 was released, so the fix is not in our current 
+> > > kernel-3.3.0-0.rc6.1.mga2, but it will be fixed in the next build.
+> > 
+> > Thanks, that's great, I will test the next build and then report back 
+> > how that works with my Cedar Trail board.
+> 
+> Hi, I noticed a new kernel packages showed up in the cauldron repo 
+> (3.3rc7) so I tried it immediately (reinstalled cauldron from scratch as 
+> I had overwritten the previous install with other distro tests) using 
+> the boot.iso image, but the video behaviour at boot is still the same, 
+> the monitor still goes into no-signal standby as soon as the drm stuff 
+> is started.
+
+Just for future reference for anyone who might come across this thread 
+in the ML archives facing the same issue:
+
+I solved this, the GMA 3600 kernel DRM driver in 3.3.0 (as included in 
+Mageia) always assumes a LVDS panel is present (as would be the case 
+on netbooks but not on mini-ITX boards) and for some reason it defaults 
+to a 1920x1080 panel.
+To avoid this and therefore to be able to use the other video outputs 
+(VGA, hdmi) at other resolutions the following kernel parameter needs to 
+be appended on the grub kernel line:
+
+video=LVDS-1:d
+
+This will force disable the LVDS port and with that parameter Mageia 2 
+works fine on a Cedarview Atom DN2800MT board.
+
+This is a shortcoming of the kernel module (not specific to Mageia), 
+Alan Cox is aware of it and I guess it will eventually be fixed.
+
+For anyone interested the xorg.conf I used is here (the monitor 
+section is specific to my monitor, hence will need adapting):
+http://pastebin.com/X7mpEF3x
+
+Also for anyone interested I have done some power draw measurements of 
+the Intel DN2800MT Cedarview Atom board comparing Mageia 2 beta with 
+some other distros (and Win 7), the results are here:
+
+http://www.linuxtech.net/reviews/intel_DN2800MT_cedarview_atom_power_draw.html
+
+
+