the whitescreen you encounter is probably a bug.
to get further with debugging this:
try to restart with i915 and fbcon built into the kernel and modesetting
switched on (in your .config or via kernel commandline: i915.modeset=1 )
as well as the kernel commandline drm.debug=12 (probably needs some
debugging option for drm turned on in your .config )
then post your resulting dmesg here and/or on
dri-devel@lists.sourceforge.net (which is the list mentioned in the
kernel MAINTAINERS file for the drm drivers )
Thanks for this info.
Okay, I cross-post now to dri-devel. For readers there: I have an embedded
device with a fixed 800x600 LCD display. Kernel is vanilla 2.6.33 from
kernel.org, for the exact hardware see lspci output below.
My real problem is that with an older kernel / older X11 the xserver-xorg-
video-i810 used to work. But with current kernel and current X11 the xserver-
xorg-video-intel driver (from Debian unstable) doesn't work at all, it hard-
locks my board - i have to reset. So I first thougth about getting a
framebuffer from Linux kernel. If the kernel itself can turn the intel
graphics to 800x600 frame-buffer mode, I think I have the first step done.
Unfortunately, modprobing i915 only yields me a totally white screen, but the
white screen disappears after a short period of time.
Apparently the framebuffer is now turned on, e.g. cat /sbin/init /dev/fb0
brings garbage (as expected) to the window.
Now my question is if / how I can disable this white-screen.
-
# modprobe drm debug=12
# modprobe i915 modeset=1
... now I have a totally white screen ... for about one second ...
# lsmod
Module Size Used by
i915 195424 1
drm_kms_helper 20496 1 i915
drm 105440 2 i915,drm_kms_helper
i2c_algo_bit3668 1 i915
button 2852 1 i915
video 12332 1 i915
backlight 1972 1 video
output 848 1 video
# dmesg
[drm] Initialized drm 1.1.0 20060810
input: Power Button as /class/input/input2
ACPI: Power Button [PWRB]
input: Power Button as /class/input/input3
ACPI: Power Button [PWRF]
i915 :00:02.0: PCI INT A - GSI 16 (level, low) - IRQ 16
i915 :00:02.0: setting latency timer to 64
[drm] set up 31M of stolen space
[drm:parse_general_definitions], crt_ddc_bus_pin: 2
[drm:parse_lfp_panel_data], Found panel mode in BIOS VBT tables:
[drm:drm_mode_debug_printmodeline], Modeline 0:800x600 0 4 800 840 968
1056 600 601 605 628 0x8 0x0
[drm:parse_sdvo_device_mapping], No SDVO device info is found in VBT
[drm:intel_modeset_init], 2 display pipes available.
[drm:ch7xxx_init], Detected CH7301 chipset, vendor/device ID 0x95/0x17
[drm] initialized overlay support
[drm:drm_helper_probe_single_connector_modes], VGA-1
[drm:intel_update_watermarks], plane A (pipe 0) clock: 31500
[drm:i9xx_get_fifo_size], FIFO size - (0x00015455) A: 85
[drm:i9xx_get_fifo_size], FIFO size - (0x00015455) B: -45
[drm:intel_calculate_wm], FIFO entries required for mode: 19
[drm:intel_calculate_wm], FIFO watermark level: 64
[drm:intel_calculate_wm], FIFO entries required for mode: 0
[drm:intel_calculate_wm], FIFO watermark level: -47
[drm:i9xx_update_wm], FIFO watermarks - A: 63, B: 1
[drm:i9xx_update_wm], Setting FIFO watermarks - A: 63, B: 1, C: 2, SR 1
[drm:intel_crtc_mode_set], Mode for pipe A:
[drm:drm_mode_debug_printmodeline], Modeline 0:640x480 0 31500 640 664 704
832 480 489 491 520 0x10 0xa
[drm:intel_pipe_set_base], No FB bound
[drm:intel_update_watermarks], plane A (pipe 0) clock: 31500
[drm:i9xx_get_fifo_size], FIFO size - (0x00015455) A: 85
[drm:i9xx_get_fifo_size], FIFO size - (0x00015455) B: -45
[drm:intel_calculate_wm], FIFO entries required for mode: 19
[drm:intel_calculate_wm], FIFO watermark level: 64
