Marc Shapiro composed on 2015-11-30 23:11 (UTC-0800):
Alright. Knowing nothing about the inner workings of X, I can at least
look through the two log files (in my previous post) and see where they
suddenly go in very different directions.
Using the numbers down the left-hand side of the logs (I don't know what
they actually are, but they seem to be ascending, so I will use them as
markers), at 32.959 in the Wheezy log and at 2271.289 in the Jessie log
they both say:
(++) using VT number 7
a few lines below that, in the Wheezy log:
[ 32.974] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 32.974] compiled for 1.12.4, module version = 0.0.2
[ 32.974] ABI class: X.Org Video Driver, version 12.1
[ 32.975] (II) RADEON(0): TOTO SAYS 00000000fddc0000
[ 32.975] (II) RADEON(0): MMIO registers at 0x00000000fddc0000: size 128KB
[ 32.975] (II) RADEON(0): PCI bus 1 card 0 func 0
[ 32.975] (II) RADEON(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 24/32
[ 32.975] (==) RADEON(0): Depth 24, (--) framebuffer bpp 32
[ 32.975] (II) RADEON(0): Pixel depth = 24 bits stored in 4 bytes (32 bpp pixmaps)
[ 32.975] (==) RADEON(0): Default visual is TrueColor
SKIP
[ 33.024] (II) RADEON(0): Detected total video RAM=1048576K, accessible=262144K (PCI BAR=262144K)
and in the Jessie log:
[ 2271.291] (II) Module fbdevhw: vendor="X.Org Foundation"
[ 2271.291] compiled for 1.16.4, module version = 0.0.2
[ 2271.291] ABI class: X.Org Video Driver, version 18.0
[ 2271.291] (**) FBDEV(2): claimed PCI slot 1@0:0:0
[ 2271.291] (II) FBDEV(2): using default device
[ 2271.291] (WW) Falling back to old probe method for vesa
[ 2271.291] (EE) Screen 0 deleted because of no matching config section.
[ 2271.291] (II) UnloadModule: "radeon"
[ 2271.291] (EE) Screen 0 deleted because of no matching config section.
[ 2271.291] (II) UnloadModule: "modesetting"
[ 2271.291] (II) FBDEV(0): Creating default Display subsection in Screen section
"Default Screen Section" for depth/fbbpp 16/16
[ 2271.291] (==) FBDEV(0): Depth 16, (==) framebuffer bpp 16
[ 2271.291] (==) FBDEV(0): RGB weight 565
[ 2271.291] (==) FBDEV(0): Default visual is TrueColor
[ 2271.291] (==) FBDEV(0): Using gamma correction (1.0, 1.0, 1.0)
[ 2271.291] (II) FBDEV(0): hardware: simple (video memory: 1536kB)
[ 2271.291] (II) FBDEV(0): checking modes against framebuffer device...
[ 2271.291] (II) FBDEV(0): checking modes against monitor...
[ 2271.291] (--) FBDEV(0): Virtual size is 1024x768 (pitch 1024)
[ 2271.291] (**) FBDEV(0): Built-in mode "current"
[ 2271.291] (==) FBDEV(0): DPI set to (96, 96)
In Wheezy, the graphics card seems to have been found and a depth of
24bpp is being used by RADEON(0) with a GB of graphics memory, while in
Jessie, Screen 0 is getting deleted and the radeon module is removed.
Instead of RADEON(0) we see FBDEV(0), instead of 24bbp, only 16bbp is
being used. Only 1536kB of video memory is being used and the screen
size is set to "Virtual size is 1024x768 (pitch 1024)".
FBDEV doesn't ever support 1920x1080 AFAIK. Video RAM and bpp are non-issues
here. What needs to be determined is why RADEON is not being used in Jessie.
FBDEV is a grossly inferior fallback.
I don't know enough to determine what is causing these differences, let
alone how to correct the problem. If someone else can figure out a
solution I would be most grateful.
You haven't provided everything requested. We don't know which gfxcard you
have, which 'lspci | grep VGA' would report. Your excerpts from Xorg.0.logs
don't have other info that may be required to help, such as kernel cmdline,
which could be the reason why RADEON is not used. Another possibility is that
Jessie provides firmware your ATI gfxcard requires in a separate firmware
package that is not installed, or maybe the ATI driver package didn't get
installed at all. Read through
https://wiki.debian.org/AtiHowTo#Troubleshooting and you may not need any
more help from us.