Dear intel-experts,
a while ago I reported that the latest kernel from intel-drm-nightly
broke operations on i830 completely. In the meantime,
I found the reason. The trouble is in intel_crtcl_init():
static void intel_crtc_init(struct drm_device *dev, int pipe)
{
....
/*
* On gen2/3 only plane A can do fbc, but the panel fitter and lvds
port
* is hooked to plane B. Hence we want plane A feeding pipe B.
*/
intel_crtc->pipe = pipe;
intel_crtc->plane = pipe;
if (IS_MOBILE(dev) && IS_GEN3(dev)) {
DRM_DEBUG_KMS("swapping pipes & planes for FBC\n");
intel_crtc->plane = !pipe;
}
The new code has here the condition "IS_MOBILE(dev) &&
INTEL_INFO(dev)->gen < 4", which however, gives a nonworking
display on my Fujitsu-Siemens. Apparently, this swap is not correct. It
might do the right thing on gen3 (I do not have a
gen3-based system so I cannot verify), but it does not work on GEN2. The
check (as above) conditioned on IS_GEN3() only
restores a working display on this system.
Two additional observations:
1) Panning did not work on i830 due to an incorrect watermark setting.
The watermark register must be at least 6 *on this specific machine*. On
the R31, it had to be at least four.
2) I do not seem to need the PIPE_A workaround on this Fujitsu laptop.
It also boots with disabling the quirk. I have not tested suspend to
ram, but it did not work before, and it likely does not work now.
Probably the pipe A quirk is only required for suspend to ram?
Even without the pipe A quirk, the bios seems to keep pipe A busy. At
least this is what I get from xrandr:
Screen 0: minimum 320 x 200, current 2048 x 1536, maximum 2048 x 2048
VGA1 unknown connection (normal left inverted right x axis y axis)
1360x768 59.8
1152x864 60.0
1024x768 60.0
800x600 60.3
640x480 59.9
DVI1 connected 2048x1536+0+0 (normal left inverted right x axis y axis)
0mm x 0mm panning 2048x1536+0+0
1024x768 60.0*
800x600 60.3 56.2
640x480 59.9
Greetings and Happy New Year,
Thomas
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
http://lists.freedesktop.org/mailman/listinfo/intel-gfx
