LVDS on 855gm stays black (was: Speeding up X's start time)

Sascha Hlusiak saschahlusiak at arcor.de
Tue Jul 3 11:13:15 PDT 2007


> Have you tried the current development version? I've made several
> patches for i855 LVDS and it now works on at least a few models.
>
> If current git master fails, please tell us what kind of laptop you have
> and what the resolution of the LVDS panel is.

It seems to be a problem with the EDID. If the LVDS is switched off before 
xserver start, the intel driver can't get the EDID and assumes that whatever 
is currently programmed is the correct mode. 

With this "patch" against 2.1.0, the display does not stay black anymore:


diff --git a/src/i830_lvds.c b/src/i830_lvds.c
index e2c6e3c..2c2da5f 100644
--- a/src/i830_lvds.c
+++ b/src/i830_lvds.c
@@ -514,7 +514,7 @@ i830_lvds_init(ScrnInfoPtr pScrn)
     /* If we didn't get EDID, try checking if the panel is already turned on.
      * If so, assume that whatever is currently programmed is the correct 
mode.
      */
-    if (dev_priv->panel_fixed_mode == NULL) {
+    /*if (dev_priv->panel_fixed_mode == NULL)*/ {
        CARD32 lvds = INREG(LVDS);
        int pipe = (lvds & LVDS_PIPEB_SELECT) ? 1 : 0;
        xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(pScrn);



This is the EDID part of my Xorg.log when the LVDS is on:

(II) intel(0): EDID for output LVDS
(II) intel(0): Manufacturer: HTC  Model: 1c43  Serial#: 540151940
(II) intel(0): Year: 2004  Week: 22
(II) intel(0): EDID Version: 1.3
(II) intel(0): Digital Display Input
(II) intel(0): Max H-Image Size [cm]: horiz.: 31  vert.: 23
(II) intel(0): Gamma: 2.20
(II) intel(0): No DPMS capabilities specified; RGB/Color Display
(II) intel(0): First detailed timing is preferred mode
(II) intel(0): redX: 0.590 redY: 0.330   greenX: 0.300 greenY: 0.550
(II) intel(0): blueX: 0.140 blueY: 0.130   whiteX: 0.310 whiteY: 0.330
(II) intel(0): Manufacturer's mask: 0
(II) intel(0): Supported additional Video Mode:
(II) intel(0): clock: 65.0 MHz   Image Size:  305 x 228 mm
(II) intel(0): h_active: 1024  h_sync: 1048  h_sync_end 1696 h_blank_end 1344 
h_border: 0
(II) intel(0): v_active: 768  v_sync: 771  v_sync_end 777 v_blanking: 806 
v_border: 0
(II) intel(0):  Hitachi
(II) intel(0):  TX38D81VC1CA
(II) intel(0): EDID (in hex):
(II) intel(0):  00ffffffffffff002283431c84103220
(II) intel(0):  160e0103801f17780a2fd697544c8c23
(II) intel(0):  214f5400000001010101010101010101
(II) intel(0):  01010101010164190040410026301888
(II) intel(0):  362031e4100000180000000f00042810
(II) intel(0):  d0010a000032ff027400000000fe0048
(II) intel(0):  697461636869202020202000000000fe
(II) intel(0):  00545833384438315643314341000041
(II) intel(0): EDID vendor "HTC", prod id 7235


Attached also the output of xrandr --verbose with the EDID part enabled and 
disabled. Doesn't seem suspicious to me.


Sascha
-------------- next part --------------
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1024 x 1024
VGA disconnected (normal left inverted right)
	Identifier: 0x43
	Timestamp:  -1925310127
	Subpixel:   unknown
	Clones:     TMDS
	CRTCs:      0 1
LVDS connected 1024x768+0+0 normal (normal left inverted right) 305mm x 228mm
	Identifier: 0x44
	Timestamp:  -1925310127
	Subpixel:   horizontal rgb
	Clones:    
	CRTC:       1
	CRTCs:      1
	EDID_DATA:
		00ffffffffffff002283431c84103220
		160e0103801f17780a2fd697544c8c23
		214f5400000001010101010101010101
		01010101010164190040410026301888
		362031e4100000180000000f00042810
		d0010a000032ff027400000000fe0048
		697461636869202020202000000000fe
		00545833384438315643314341000041
	BACKLIGHT: 0 (0x00000000) range:  (0,0)
  1024x768 (0x5f)   65.0MHz
        h: width  1024 start 1048 end 1696 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  1024x768 (0x4a)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x4f)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x54)   25.2MHz
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
TMDS disconnected (normal left inverted right)
	Identifier: 0x45
	Timestamp:  -1925310127
	Subpixel:   horizontal rgb
	Clones:     VGA
	CRTCs:      0 1
  1024x768 (0x46)   64.2MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   47.8KHz
        v: height  768 start  771 end  777 total  806           clock   59.3Hz
-------------- next part --------------
Screen 0: minimum 320 x 200, current 1024 x 768, maximum 1024 x 1024
VGA disconnected (normal left inverted right)
	Identifier: 0x43
	Timestamp:  -1925250770
	Subpixel:   unknown
	Clones:     TMDS
	CRTCs:      0 1
LVDS connected 1024x768+0+0 normal (normal left inverted right) 305mm x 228mm
	Identifier: 0x44
	Timestamp:  -1925250770
	Subpixel:   horizontal rgb
	Clones:    
	CRTC:       1
	CRTCs:      1
	EDID_DATA:
		00ffffffffffff002283431c84103220
		160e0103801f17780a2fd697544c8c23
		214f5400000001010101010101010101
		01010101010164190040410026301888
		362031e4100000180000000f00042810
		d0010a000032ff027400000000fe0048
		697461636869202020202000000000fe
		00545833384438315643314341000041
	BACKLIGHT: 0 (0x00000000) range:  (0,0)
  1024x768 (0x46)   65.0MHz
        h: width  1024 start 1048 end 1696 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  1024x768 (0x4a)   65.0MHz
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock   48.4KHz
        v: height  768 start  771 end  777 total  806           clock   60.0Hz
  800x600 (0x4f)   40.0MHz
        h: width   800 start  840 end  968 total 1056 skew    0 clock   37.9KHz
        v: height  600 start  601 end  605 total  628           clock   60.3Hz
  640x480 (0x54)   25.2MHz
        h: width   640 start  656 end  752 total  800 skew    0 clock   31.5KHz
        v: height  480 start  490 end  492 total  525           clock   59.9Hz
TMDS disconnected (normal left inverted right)
	Identifier: 0x45
	Timestamp:  -1925250770
	Subpixel:   horizontal rgb
	Clones:     VGA
	CRTCs:      0 1
-------------- next part --------------
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