i915 uses only 8mb video ram and disables xv, dri

[Thorben Kröger]

I have tried almost everything, but I just can't get xvideo and direct 
rendering to work with the i810 driver using Xorg 6.8.99.15. 

System:    gentoo-linux
Kernel:    gentoo-sources-2.6.12-r6 
Xorg:      xorg-x11-6.8.99.15 
Hardware:  Samsung X20 XVM 1600 V which has i915 chipset witch 128mb shared 
memory graphics using PCI-Express and a 1400x1050 display

Note that I use 855resolution to trick the VBIOS into believing there is a 
1400x1050 mode.

mercury thorben # dmesg | grep -i agpgart
Linux agpgart interface v0.101 (c) Dave Jones
agpgart: Detected an Intel 915GM Chipset.
agpgart: Detected 7932K stolen memory.
agpgart: AGP aperture is 256M @ 0xc0000000

Stolen memory? What's that about?

mercury thorben # dmesg | grep -i drm
[drm] Initialized drm 1.0.0 20040925
[drm] Initialized i915 1.1.0 20040405 on minor 0: Intel Corporation Mobile 
915GM/GMS/910GML Express Graphics Controller

This looks all right, doesn't it?

Now on to the Xorg.0.log:

Here it scans the PCI-Express bus:
(--) PCI:*(0:2:0) Intel Corporation Mobile 915GM/GMS/910GML Express Graphics 
Controller rev 3, Mem @ 0xb0080000/19, 0xc0000000/28, 0xb0000000/18, I/O @ 
0x1800/3
(--) PCI: (0:2:1) Intel Corporation Mobile 915GM/GMS/910GML Express Graphics 
Controller rev 3, Mem @ 0x40000000/19

And loads the correct driver for the i915 chipset:
(II) I810: Driver for Intel Integrated Graphics Chipsets: i810, i810-dc100,
	i810e, i815, i830M, 845G, 852GM/855GM, 865G, 915G, E7221 (i915),
	915GM, 945G
(--) Chipset 915GM found

Now, this is bad:
II) Loading sub module "int10"
(II) LoadModule: "int10"
(II) Reloading /usr/lib/modules/linux/libint10.so
(II) I810(0): initializing int10
(WW) I810(0): Bad V_BIOS checksum
(II) I810(0): Primary V_BIOS segment is: 0xc000
(II) I810(0): VESA BIOS detected
(II) I810(0): VESA VBE Version 3.0
(II) I810(0): VESA VBE Total Mem: 7872 kB
(II) I810(0): VESA VBE OEM: Intel(r)915GM/910ML/915MS Graphics Chip 
Accelerated VGA BIOS
(II) I810(0): VESA VBE OEM Software Rev: 1.0
(II) I810(0): VESA VBE OEM Vendor: Intel Corporation
(II) I810(0): VESA VBE OEM Product: Intel(r)915GM/910ML/915MS Graphics 
Controller
(II) I810(0): VESA VBE OEM Product Rev: Hardware Version 0.0
(II) I810(0): Integrated Graphics Chipset: Intel(R) 915GM
(--) I810(0): Chipset: "915GM"
(--) I810(0): Linear framebuffer at 0xC0000000
(--) I810(0): IO registers at addr 0xB0080000
(II) I810(0): 2 display pipes available.
(II) I810(0): detected 7932 kB stolen memory.
(II) I810(0): I830CheckAvailableMemory: -545582944 kB available

Huh?? And why I830??

(WW) I810(0): /dev/agpgart is either not available, or no memory is available
for allocation.  Using pre-allocated memory only.

mercury thorben # ls -l /dev/agpgart
lrwxrwxrwx  1 root root 12 Jul 22  2005 /dev/agpgart -> misc/agpgart

(II) I810(0): Monitoring connected displays enabled
(WW) I810(0): VideoRAM reduced to 7932 kByte (limited to available sysmem)
(--) I810(0): Pre-allocated VideoRAM: 7932 kByte
(--) I810(0): VideoRAM: 7932 kByte
(==) I810(0): video overlay key set to 0x83e
(**) I810(0): page flipping disabled

Looks like Xorg only wants to use 8MB RAM, but that is not enough for direct 
rendering etc. to be enabled 
 
(--) I810(0): Maximum space available for video modes: 7784 kByte

II) I810(0): LaptopTFT: Using hsync range of 60.00-66.32 kHz
(II) I810(0): LaptopTFT: Using vrefresh value of 60.00 Hz
(II) I810(0): Correcting stride (1400 -> 2816)
(II) I810(0): 15440 kBytes additional video memory is required to
	enable tiling mode for DRI.
(II) I810(0): 3040 kBytes additional video memory is required to enable DRI.
(II) I810(0): Disabling DRI.

And here goes DRI support :-(

(II) Reloading /usr/lib/modules/linux/libint10.so
(II) I810(0): initializing int10
(WW) I810(0): Bad V_BIOS checksum
(II) I810(0): Primary V_BIOS segment is: 0xc000
(II) I810(0): VESA BIOS detected
(II) I810(0): VESA VBE Version 3.0
(II) I810(0): VESA VBE Total Mem: 7872 kB
(II) I810(0): VESA VBE OEM: Intel(r)915GM/910ML/915MS Graphics Chip 
Accelerated VGA BIOS
(II) I810(0): VESA VBE OEM Software Rev: 1.0
(II) I810(0): VESA VBE OEM Vendor: Intel Corporation
(II) I810(0): VESA VBE OEM Product: Intel(r)915GM/910ML/915MS Graphics 
Controller
(II) I810(0): VESA VBE OEM Product Rev: Hardware Version 0.0
(--) I810(0): Xv is disabled because it needs 2D accel and AGPGART.

And xvideo is gone as well :-(

This is what is relevant in the Character devices section in the kernel: 
<*> /dev/agpgart (AGP Support) 
<*>   Intel 440LX/BX/GX, I8xx and E7x05 chipset support 
<*> Direct Rendering Manager (XFree86 4.1.0 and higher DRI support) 
<*>   Intel 830M, 845G, 852GM, 855GM, 865G (i915 driver) 

And here DRI and Device section of my xorg.conf: 

Section "DRI" 
   Mode 0666 
EndSection 
 
Section "Device" 
   Identifier  "i915Chipset" 
   Driver      "i810" 
   VideoRam    131072 
   Option      "NoAccel"       "false" 
   Option      "DRI"           "true" 
 EndSection 

Any ideas? I hate having a 1,6Ghz CPU and not being able to watch DVDs ;-)