Then,I realize that update make some enhancement to X and associated things are not getting updated with it.
So, instinctively poking at the log file tell me that "ABI version of so many thing ,related to X driver is mismatching with the server version" and then the obvious thing a little google search reveal that too.Something like this in log file shows:
38.004] (EE) module ABI major version (10) doesn't match the server's version (11)
[ 38.004] (II) UnloadModule: "vesa"
[ 38.004] (II) Unloading vesa
[ 38.005] (EE) Failed to load module "vesa" (module requirement mismatch, 0)
[ 38.005] (II) LoadModule: "fbdev"
[ 38.005] (II) Loading /usr/lib/xorg/modules/drivers/fbdev_drv.so
[ 38.005] (II) Module fbdev: vendor="X.Org Foundation"
[ 38.005] compiled for 1.10.2, module version = 0.4.2
[ 38.005] ABI class: X.Org Video Driver, version 10.0
[ 38.005] (EE) module ABI major version (10) doesn't match the server's version (11)
[ 38.005] (II) UnloadModule: "fbdev"
[ 38.005] (II) Unloading fbdev
[ 38.005] (EE) Failed to load module "fbdev" (module requirement mismatch, 0)
[ 38.005] (II) intel: Driver for Intel Integrated Graphics Chipsets: i810,
i810-dc100, i810e, i815, i830M, 845G, 854, 852GM/855GM, 865G, 915G,
E7221 (i915), 915GM, 945G, 945GM, 945GME, Pineview GM, Pineview G,
965G, G35, 965Q, 946GZ, 965GM, 965GME/GLE, G33, Q35, Q33, GM45,
4 Series, G45/G43, Q45/Q43, G41, B43, B43, Clarkdale, Arrandale,
Sandybridge Desktop (GT1), Sandybridge Desktop (GT2),
Sandybridge Desktop (GT2+), Sandybridge Mobile (GT1),
Sandybridge Mobile (GT2), Sandybridge Mobile (GT2+),
Sandybridge Server, Ivybridge Mobile (GT1), Ivybridge Mobile (GT2),
Ivybridge Desktop (GT1), Ivybridge Desktop (GT2), Ivybridge Server
[ 38.005] (++) using VT number 7
[ 38.038] (EE) No devices detected.
Fatal server error:
[ 38.038] no screens found
Please consult the The X.Org Foundation support
[ 38.038] Please also check the log file at "/var/log/Xorg.1.log" for additional information.
Now the time to rebuild the X11 drivers ,because I got new X server to match with it.Did it like this :
bhaskar@GentooLinux_15:11:04_Tue Jan 03:~> sudo emerge -1 $(qlist -IC x11-drivers)
That is numeric one to the emerge flag...means oneshot..means not put an entry in world file...
Once it finish I reboot the machine and voila...the X display come back!!
Hope this will help.