Hi, on my machine, I have 2 monitors attached, they are seen as HMDI connectors by the software. The 1st monitor is connected using a DVI-D cable while the second one uses the HDMI port of the machine and connects to the monitor using a DVI-D connector. I want to use the frame buffer only on the first monitor while the machine is initially booting and then use both monitors while Xorg is running. As mentioned near the end of this page: http://intellinuxgraphics.org/documentation.html it's possible to control this behavior using the kernel command line. I want to force the resolution of the first monitor to 1024x768 while the second monitor is disabled. I used the following to do it: video=HDMI-A-1:1024x768 video=HDMI-A-2:d It's almost working, the second monitor goes black as expected and the first one switch to 1024x768. The first problem with that configuration, is that every 10 seconds, the first monitor will go black for 3 seconds. If I remove "video=HDMI-A-2:d" or the second monitor is physically not attached, I don't have this problem. If I add "drm.debug=0x04" to the kernel command line, each time the first monitor goes black, I get the following debugging output in 'dmesg': --- [ 61.335798] [drm:intel_ironlake_crt_detect_hotplug], ironlake hotplug adpa=0xf40000, result 0 [ 61.335805] [drm:intel_crt_detect], CRT not detected via hotplug [ 61.335819] [drm:output_poll_execute], [CONNECTOR:7:VGA-1] status updated from 2 to 2 [ 61.374359] [drm:output_poll_execute], [CONNECTOR:10:HDMI-A-1] status updated from 1 to 1 [ 61.376914] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.381256] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.385252] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.386696] [drm:intel_dp_detect], DPCD: 0000000000000000 [ 61.386702] [drm:output_poll_execute], [CONNECTOR:13:DP-1] status updated from 2 to 2 [ 61.425164] [drm:output_poll_execute], [CONNECTOR:16:HDMI-A-2] status updated from 2 to 1 [ 61.427715] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.432170] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.436156] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.437600] [drm:intel_dp_detect], DPCD: 0000000000000000 [ 61.437606] [drm:output_poll_execute], [CONNECTOR:17:DP-2] status updated from 2 to 2 [ 61.437653] [drm:drm_fb_helper_hotplug_event], [ 61.437656] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] [ 61.437660] [drm:intel_ironlake_crt_detect_hotplug], ironlake hotplug adpa=0xf40000, result 0 [ 61.437663] [drm:intel_crt_detect], CRT not detected via hotplug [ 61.437667] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] disconnected [ 61.437670] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:10:HDMI-A-1] [ 61.514713] [drm:drm_edid_to_eld], ELD: no CEA Extension found [ 61.514727] [drm:drm_mode_debug_printmodeline], Modeline 31:"1280x960" 0 108000 1280 1376 1488 1800 960 961 964 1000 0x40 0x5 [ 61.514734] [drm:drm_mode_prune_invalid], Not using 1280x960 mode 12 [ 61.514737] [drm:drm_mode_debug_printmodeline], Modeline 26:"1600x1200" 0 162000 1600 1664 1856 2160 1200 1201 1204 1250 0x40 0x5 [ 61.514741] [drm:drm_mode_prune_invalid], Not using 1600x1200 mode 12 [ 61.514743] [drm:drm_mode_debug_printmodeline], Modeline 25:"1280x1024" 0 108000 1280 1328 1440 1688 1024 1025 1028 1066 0x40 0x5 [ 61.514747] [drm:drm_mode_prune_invalid], Not using 1280x1024 mode 12 [ 61.514749] [drm:drm_mode_debug_printmodeline], Modeline 24:"1280x800" 0 83500 1280 1352 1480 1680 800 803 809 831 0x40 0x6 [ 61.514753] [drm:drm_mode_prune_invalid], Not using 1280x800 mode 12 [ 61.514755] [drm:drm_mode_debug_printmodeline], Modeline 23:"1680x1050" 0 119000 1680 1728 1760 1840 1050 1053 1059 1080 0x40 0x9 [ 61.514758] [drm:drm_mode_prune_invalid], Not using 1680x1050 mode 12 [ 61.514761] [drm:drm_mode_debug_printmodeline], Modeline 22:"1440x900" 0 106000 1440 1520 1672 1904 900 903 909 934 0x40 0x6 [ 61.514764] [drm:drm_mode_prune_invalid], Not using 1440x900 mode 12 [ 61.514767] [drm:drm_mode_debug_printmodeline], Modeline 21:"1366x768" 0 85500 1366 1436 1579 1792 768 771 774 798 0x48 0x5 [ 61.514770] [drm:drm_mode_prune_invalid], Not using 1366x768 mode 11 [ 61.514774] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:10:HDMI-A-1] probed modes : [ 61.514777] [drm:drm_mode_debug_printmodeline], Modeline 30:"1024x768" 60 65000 1024 1048 1184 1344 768 771 777 806 0x40 0xa [ 61.514780] [drm:drm_mode_debug_printmodeline], Modeline 27:"800x600" 60 40000 800 840 968 1056 600 601 605 628 0x40 0x5 [ 61.514784] [drm:drm_mode_debug_printmodeline], Modeline 28:"800x600" 56 36000 800 824 896 1024 600 601 603 625 0x40 0x5 [ 61.514788] [drm:drm_mode_debug_printmodeline], Modeline 29:"640x480" 60 25200 640 656 752 800 480 490 492 525 0x40 0xa [ 61.514792] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:13:DP-1] [ 61.517410] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.521005] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.524980] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.526435] [drm:intel_dp_detect], DPCD: 0000000000000000 [ 61.526442] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:13:DP-1] disconnected [ 61.526455] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:HDMI-A-2] [ 61.526460] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:HDMI-A-2] disconnected [ 61.526466] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:17:DP-2] [ 61.529075] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.532982] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.536964] [drm:intel_dp_aux_ch], dp_aux_ch timeout status 0x5143003f [ 61.538412] [drm:intel_dp_detect], DPCD: 0000000000000000 [ 61.538418] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:17:DP-2] disconnected [ 61.538422] [drm:drm_setup_crtcs], [ 61.538437] [drm:drm_enable_connectors], connector 7 enabled? no [ 61.538443] [drm:drm_enable_connectors], connector 10 enabled? yes [ 61.538447] [drm:drm_enable_connectors], connector 13 enabled? no [ 61.538457] [drm:drm_enable_connectors], connector 16 enabled? no [ 61.538460] [drm:drm_enable_connectors], connector 17 enabled? no [ 61.538462] [drm:drm_target_preferred], looking for cmdline mode on connector 10 [ 61.538464] [drm:drm_target_preferred], found mode 1024x768 [ 61.538466] [drm:drm_setup_crtcs], picking CRTCs for 8192x8192 config [ 61.538470] [drm:drm_setup_crtcs], desired mode 1024x768 set on crtc 3 [ 61.538475] [drm:drm_crtc_helper_set_config], [ 61.538477] [drm:drm_crtc_helper_set_config], [CRTC:3] [FB:32] #connectors=1 (x y) (0 0) [ 61.538487] [drm:drm_crtc_helper_set_config], crtc changed, full mode switch [ 61.538489] [drm:drm_crtc_helper_set_config], [CONNECTOR:10:HDMI-A-1] to [CRTC:3] [ 61.538492] [drm:drm_crtc_helper_set_config], attempting to set mode from userspace [ 61.538494] [drm:drm_mode_debug_printmodeline], Modeline 20:"1024x768" 60 65000 1024 1048 1184 1344 768 771 777 806 0x40 0xa [ 61.538499] [drm:drm_crtc_helper_set_mode], [CRTC:3] [ 61.590314] [drm:intel_wait_for_vblank], vblank wait timed out [ 61.622665] [drm:sandybridge_update_wm], FIFO watermarks For pipe A - plane 5, cursor: 6 [ 61.622669] [drm:ironlake_check_srwm], watermark 1: display plane 9, fbc lines 3, cursor 6 [ 61.622672] [drm:ironlake_check_srwm], watermark 2: display plane 11, fbc lines 3, cursor 6 [ 61.622675] [drm:ironlake_check_srwm], watermark 3: display plane 47, fbc lines 3, cursor 6 [ 61.622678] [drm:intel_update_fbc], [ 61.622921] [drm:intel_choose_pipe_bpp_dither], forcing bpc to 8 for HDMI [ 61.622924] [drm:intel_choose_pipe_bpp_dither], setting pipe bpc to 8 (max display bpc 8) [ 61.622926] [drm:ironlake_crtc_mode_set], Mode for pipe 0: [ 61.622929] [drm:drm_mode_debug_printmodeline], Modeline 20:"1024x768" 60 65000 1024 1048 1184 1344 768 771 777 806 0x40 0xa [ 61.675156] [drm:intel_wait_for_vblank], vblank wait timed out [ 61.675162] [drm:ironlake_update_plane], Writing base 00064000 00000000 0 0 4096 [ 61.675180] [drm:intel_update_fbc], [ 61.727055] [drm:intel_wait_for_vblank], vblank wait timed out [ 61.727060] [drm:sandybridge_update_wm], FIFO watermarks For pipe A - plane 5, cursor: 6 [ 61.727065] [drm:ironlake_check_srwm], watermark 1: display plane 9, fbc lines 3, cursor 6 [ 61.727078] [drm:ironlake_check_srwm], watermark 2: display plane 11, fbc lines 3, cursor 6 [ 61.727084] [drm:ironlake_check_srwm], watermark 3: display plane 47, fbc lines 3, cursor 6 [ 61.727091] [drm:drm_crtc_helper_set_mode], [ENCODER:9:TMDS-9] set [MODE:20:1024x768] [ 61.727105] [drm:sandybridge_update_wm], FIFO watermarks For pipe A - plane 5, cursor: 6 [ 61.727108] [drm:ironlake_check_srwm], watermark 1: display plane 9, fbc lines 3, cursor 6 [ 61.727111] [drm:ironlake_check_srwm], watermark 2: display plane 11, fbc lines 3, cursor 6 [ 61.727113] [drm:ironlake_check_srwm], watermark 3: display plane 47, fbc lines 3, cursor 6 [ 61.778958] [drm:intel_wait_for_vblank], vblank wait timed out [ 61.830860] [drm:intel_wait_for_vblank], vblank wait timed out [ 61.831674] [drm:gen6_fdi_link_train], FDI_RX_IIR 0x100 [ 61.831677] [drm:gen6_fdi_link_train], FDI train 1 done. [ 61.832332] [drm:gen6_fdi_link_train], FDI_RX_IIR 0x600 [ 61.832336] [drm:gen6_fdi_link_train], FDI train 2 done. [ 61.832338] [drm:gen6_fdi_link_train], FDI train done. [ 61.833557] [drm:intel_update_fbc], [ 61.834067] [drm:drm_crtc_helper_set_config], Setting connector DPMS state to on [ 61.834070] [drm:drm_crtc_helper_set_config], [CONNECTOR:10:HDMI-A-1] set DPMS on [ 61.834084] [drm:drm_crtc_helper_set_config], [ 61.834086] [drm:drm_crtc_helper_set_config], [CRTC:5] [NOFB] [ 66.713024] [drm:drm_crtc_helper_set_config], [ 66.713027] [drm:drm_crtc_helper_set_config], [CRTC:3] [FB:32] #connectors=1 (x y) (0 0) [ 66.713035] [drm:drm_crtc_helper_set_config], [CONNECTOR:10:HDMI-A-1] to [CRTC:3] [ 66.713039] [drm:drm_crtc_helper_set_config], [ 66.713056] [drm:drm_crtc_helper_set_config], [CRTC:5] [NOFB] [ 66.713069] [drm:drm_crtc_helper_set_config], [ 66.713070] [drm:drm_crtc_helper_set_config], [CRTC:3] [FB:32] #connectors=1 (x y) (0 0) [ 66.713074] [drm:drm_crtc_helper_set_config], [CONNECTOR:10:HDMI-A-1] to [CRTC:3] [ 66.713085] [drm:drm_crtc_helper_set_config], [ 66.713086] [drm:drm_crtc_helper_set_config], [CRTC:3] [FB:32] #connectors=1 (x y) (0 0) [ 66.713090] [drm:drm_crtc_helper_set_config], [CONNECTOR:10:HDMI-A-1] to [CRTC:3] --- Additionally, the second monitor fails to be enabled properly in Xorg when it was disabled in frame buffer mode, even if I use: Option "Enable" "true" in the right monitor section as documented at: http://intellinuxgraphics.org/dualhead.html This is the monitor information for in "Xorg.log" when it is working properly: --- [ 76.352] (II) intel(0): Printing probed modes for output HDMI2 [ 76.352] (II) intel(0): Modeline "1360x768"x59.8 84.75 1366 1431 1567 1776 768 771 781 798 -hsync +vsync (47.7 kHz UP) [ 76.352] (II) intel(0): Modeline "1680x1050"x60.0 146.25 1680 1960 2136 2240 1050 1053 1059 1089 -hsync +vsync (65.3 kHz eP) [ 76.352] (II) intel(0): Modeline "1920x1200"x60.0 154.00 1920 1968 2000 2080 1200 1203 1209 1235 +hsync -vsync (74.0 kHz e) [ 76.352] (II) intel(0): Modeline "1600x1200"x60.0 162.00 1600 1664 1856 2160 1200 1201 1204 1250 +hsync +vsync (75.0 kHz e) [ 76.352] (II) intel(0): Modeline "1280x1024"x75.0 135.00 1280 1296 1440 1688 1024 1025 1028 1066 +hsync +vsync (80.0 kHz e) [ 76.352] (II) intel(0): Modeline "1280x1024"x60.0 108.00 1280 1328 1440 1688 1024 1025 1028 1066 +hsync +vsync (64.0 kHz e) [ 76.352] (II) intel(0): Modeline "1440x900"x59.9 106.50 1440 1520 1672 1904 900 903 909 934 -hsync +vsync (55.9 kHz e) [ 76.352] (II) intel(0): Modeline "1280x960"x60.0 108.00 1280 1376 1488 1800 960 961 964 1000 +hsync +vsync (60.0 kHz e) [ 76.352] (II) intel(0): Modeline "1280x800"x59.8 83.50 1280 1352 1480 1680 800 803 809 831 +hsync -vsync (49.7 kHz e) [ 76.352] (II) intel(0): Modeline "1152x864"x75.0 108.00 1152 1216 1344 1600 864 865 868 900 +hsync +vsync (67.5 kHz e) [ 76.352] (II) intel(0): Modeline "1024x768"x75.1 78.80 1024 1040 1136 1312 768 769 772 800 +hsync +vsync (60.1 kHz e) [ 76.352] (II) intel(0): Modeline "1024x768"x70.1 75.00 1024 1048 1184 1328 768 771 777 806 -hsync -vsync (56.5 kHz e) [ 76.352] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz e) [ 76.352] (II) intel(0): Modeline "1024x768"x87.0 44.90 1024 1032 1208 1264 768 768 776 817 interlace +hsync +vsync (35.5 kHz e) [ 76.352] (II) intel(0): Modeline "800x600"x72.2 50.00 800 856 976 1040 600 637 643 666 +hsync +vsync (48.1 kHz e) [ 76.352] (II) intel(0): Modeline "800x600"x75.0 49.50 800 816 896 1056 600 601 604 625 +hsync +vsync (46.9 kHz e) [ 76.352] (II) intel(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz e) [ 76.352] (II) intel(0): Modeline "800x600"x56.2 36.00 800 824 896 1024 600 601 603 625 +hsync +vsync (35.2 kHz e) [ 76.352] (II) intel(0): Modeline "640x480"x72.8 31.50 640 664 704 832 480 489 491 520 -hsync -vsync (37.9 kHz e) [ 76.352] (II) intel(0): Modeline "640x480"x75.0 31.50 640 656 720 840 480 481 484 500 -hsync -vsync (37.5 kHz e) [ 76.352] (II) intel(0): Modeline "640x480"x66.7 30.24 640 704 768 864 480 483 486 525 -hsync -vsync (35.0 kHz e) [ 76.352] (II) intel(0): Modeline "640x480"x60.0 25.20 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz e) [ 76.352] (II) intel(0): Modeline "720x400"x70.1 28.32 720 738 846 900 400 412 414 449 -hsync +vsync (31.5 kHz e) [ 76.378] (II) intel(0): EDID for output DP2 [ 76.378] (II) intel(0): Output VGA1 disconnected [ 76.378] (II) intel(0): Output HDMI1 connected [ 76.378] (II) intel(0): Output DP1 disconnected [ 76.378] (II) intel(0): Output HDMI2 enabled by config file [ 76.378] (II) intel(0): Output DP2 disconnected [ 76.378] (II) intel(0): Using user preference for initial modes [ 76.378] (II) intel(0): Output HDMI1 using initial mode 1366x768 [ 76.378] (II) intel(0): Output HDMI2 using initial mode 1360x768 --- And when it's not as a side effect of being disabled in frame buffer mode: --- [ 229.480] (II) intel(0): Printing probed modes for output HDMI2 [ 229.480] (II) intel(0): Modeline "1024x768"x60.0 65.00 1024 1048 1184 1344 768 771 777 806 -hsync -vsync (48.4 kHz d) [ 229.480] (II) intel(0): Modeline "800x600"x60.3 40.00 800 840 968 1056 600 601 605 628 +hsync +vsync (37.9 kHz d) [ 229.480] (II) intel(0): Modeline "640x480"x59.9 25.18 640 656 752 800 480 490 492 525 -hsync -vsync (31.5 kHz d) [ 229.505] (II) intel(0): EDID for output DP2 [ 229.505] (II) intel(0): Output VGA1 disconnected [ 229.505] (II) intel(0): Output HDMI1 connected [ 229.505] (II) intel(0): Output DP1 disconnected [ 229.505] (II) intel(0): Output HDMI2 enabled by config file [ 229.505] (II) intel(0): Output DP2 disconnected [ 229.505] (II) intel(0): Using user preference for initial modes [ 229.505] (II) intel(0): Output HDMI1 using initial mode 1366x768 [ 229.505] (II) intel(0): Output HDMI2 using initial mode 1024x768 --- I suspect in this case that the second monitor fails to enumerate all the supported modes for a reason I can't identify. I am using a software stack that is very close to the one proposed at: http://intellinuxgraphics.org/2012.07.html built from source for a x86_64 architecture using Sandybridge chipset. I also tried with the current stable kernel (3.6.9), same problem. Any ideas what could be the problem(s)? Regards, - Jonathan Ph?nix
