$ xrandr -o left
# screen goes blank
$ tail /var/log/kern.log
Feb 10 22:18:35 cedar kernel: [ 3880.200671] [drm:drm_mode_getconnector], [CONNECTOR:7:?]
Feb 10 22:18:35 cedar kernel: [ 3880.200703] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1]
Feb 10 22:18:35 cedar kernel: [ 3880.229844] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.229961] [drm:drm_mode_getconnector], [CONNECTOR:7:?]
Feb 10 22:18:35 cedar kernel: [ 3880.229985] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1]
Feb 10 22:18:35 cedar kernel: [ 3880.261866] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.262051] [drm:drm_mode_getconnector], [CONNECTOR:9:?]
Feb 10 22:18:35 cedar kernel: [ 3880.262077] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:9:LVDS-1]
Feb 10 22:18:35 cedar kernel: [ 3880.266782] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm LVDSBLC_B
Feb 10 22:18:35 cedar kernel: [ 3880.266825] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:9:LVDS-1] probed modes :
Feb 10 22:18:35 cedar kernel: [ 3880.266839] [drm:drm_mode_debug_printmodeline], Modeline 12:"1366x768" 60 75010 1366 1399 1468 1553 768 772 784 805 0x48 0xa
Feb 10 22:18:35 cedar kernel: [ 3880.266934] [drm:drm_mode_getconnector], [CONNECTOR:9:?]
Feb 10 22:18:35 cedar kernel: [ 3880.269200] [drm:drm_mode_getconnector], [CONNECTOR:14:?]
Feb 10 22:18:35 cedar kernel: [ 3880.269300] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1]
Feb 10 22:18:35 cedar kernel: [ 3880.273960] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm HDMIB
Feb 10 22:18:35 cedar kernel: [ 3880.273983] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.274095] [drm:drm_mode_getconnector], [CONNECTOR:14:?]
Feb 10 22:18:35 cedar kernel: [ 3880.274102] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1]
Feb 10 22:18:35 cedar kernel: [ 3880.278562] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm HDMIB
Feb 10 22:18:35 cedar kernel: [ 3880.278571] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.278613] [drm:drm_mode_getconnector], [CONNECTOR:16:?]
Feb 10 22:18:35 cedar kernel: [ 3880.278621] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1]
Feb 10 22:18:35 cedar kernel: [ 3880.279126] [drm:cdv_intel_dp_aux_ch], dp_aux_ch timeout status 0x51440064
Feb 10 22:18:35 cedar kernel: [ 3880.279132] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.279140] [drm:drm_mode_getconnector], [CONNECTOR:16:?]
Feb 10 22:18:35 cedar kernel: [ 3880.279145] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1]
Feb 10 22:18:35 cedar kernel: [ 3880.279649] [drm:cdv_intel_dp_aux_ch], dp_aux_ch timeout status 0x51440064
Feb 10 22:18:35 cedar kernel: [ 3880.279654] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1] disconnected
Feb 10 22:18:35 cedar kernel: [ 3880.640713] [drm:cdv_intel_single_pipe_active], pipe enabled 0
Feb 10 22:18:35 cedar kernel: [ 3880.662628] [drm:drm_mode_addfb], [FB:23]
Feb 10 22:18:35 cedar kernel: [ 3880.662684] [drm:drm_crtc_helper_set_config], 
Feb 10 22:18:35 cedar kernel: [ 3880.662690] [drm:drm_crtc_helper_set_config], [CRTC:4] [NOFB]
Feb 10 22:18:35 cedar kernel: [ 3880.662712] [drm:cdv_intel_single_pipe_active], pipe enabled 0
Feb 10 22:18:35 cedar kernel: [ 3880.682582] [drm:cdv_intel_single_pipe_active], pipe enabled 0

$ xrandr -o normal
# screen is working back
$ tail /var/log/kern.log
Feb 10 22:19:20 cedar kernel: [ 3925.034761] [drm:drm_mode_getconnector], [CONNECTOR:7:?]
Feb 10 22:19:20 cedar kernel: [ 3925.034793] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1]
Feb 10 22:19:20 cedar kernel: [ 3925.065444] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.065539] [drm:drm_mode_getconnector], [CONNECTOR:7:?]
Feb 10 22:19:20 cedar kernel: [ 3925.065559] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1]
Feb 10 22:19:20 cedar kernel: [ 3925.097495] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:7:VGA-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.097680] [drm:drm_mode_getconnector], [CONNECTOR:9:?]
Feb 10 22:19:20 cedar kernel: [ 3925.097707] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:9:LVDS-1]
Feb 10 22:19:20 cedar kernel: [ 3925.102416] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm LVDSBLC_B
Feb 10 22:19:20 cedar kernel: [ 3925.102456] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:9:LVDS-1] probed modes :
Feb 10 22:19:20 cedar kernel: [ 3925.102470] [drm:drm_mode_debug_printmodeline], Modeline 12:"1366x768" 60 75010 1366 1399 1468 1553 768 772 784 805 0x48 0xa
Feb 10 22:19:20 cedar kernel: [ 3925.102642] [drm:drm_mode_getconnector], [CONNECTOR:9:?]
Feb 10 22:19:20 cedar kernel: [ 3925.104844] [drm:drm_mode_getconnector], [CONNECTOR:14:?]
Feb 10 22:19:20 cedar kernel: [ 3925.104965] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1]
Feb 10 22:19:20 cedar kernel: [ 3925.109693] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm HDMIB
Feb 10 22:19:20 cedar kernel: [ 3925.109717] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.109844] [drm:drm_mode_getconnector], [CONNECTOR:14:?]
Feb 10 22:19:20 cedar kernel: [ 3925.109852] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1]
Feb 10 22:19:20 cedar kernel: [ 3925.114312] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter intel drm HDMIB
Feb 10 22:19:20 cedar kernel: [ 3925.114322] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:14:DVI-D-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.114349] [drm:drm_mode_getconnector], [CONNECTOR:16:?]
Feb 10 22:19:20 cedar kernel: [ 3925.114355] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1]
Feb 10 22:19:20 cedar kernel: [ 3925.114861] [drm:cdv_intel_dp_aux_ch], dp_aux_ch timeout status 0x51440064
Feb 10 22:19:20 cedar kernel: [ 3925.114867] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.114887] [drm:drm_mode_getconnector], [CONNECTOR:16:?]
Feb 10 22:19:20 cedar kernel: [ 3925.114893] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1]
Feb 10 22:19:20 cedar kernel: [ 3925.115397] [drm:cdv_intel_dp_aux_ch], dp_aux_ch timeout status 0x51440064
Feb 10 22:19:20 cedar kernel: [ 3925.115403] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:16:DP-1] disconnected
Feb 10 22:19:20 cedar kernel: [ 3925.117792] [drm:drm_mode_addfb], [FB:22]
Feb 10 22:19:20 cedar kernel: [ 3925.136137] [drm:drm_mode_setcrtc], [CRTC:4]
Feb 10 22:19:20 cedar kernel: [ 3925.136157] [drm:drm_mode_setcrtc], [CONNECTOR:9:LVDS-1]
Feb 10 22:19:20 cedar kernel: [ 3925.136164] [drm:drm_crtc_helper_set_config], 
Feb 10 22:19:20 cedar kernel: [ 3925.136168] [drm:drm_crtc_helper_set_config], [CRTC:4] [FB:22] #connectors=1 (x y) (0 0)
Feb 10 22:19:20 cedar kernel: [ 3925.136189] [drm:drm_crtc_helper_set_config], crtc has no fb, full mode set
Feb 10 22:19:20 cedar kernel: [ 3925.136194] [drm:drm_crtc_helper_set_config], encoder changed, full mode switch
Feb 10 22:19:20 cedar kernel: [ 3925.136199] [drm:drm_crtc_helper_set_config], crtc changed, full mode switch
Feb 10 22:19:20 cedar kernel: [ 3925.136203] [drm:drm_crtc_helper_set_config], [CONNECTOR:9:LVDS-1] to [CRTC:4]
Feb 10 22:19:20 cedar kernel: [ 3925.136209] [drm:drm_crtc_helper_set_config], attempting to set mode from userspace
Feb 10 22:19:20 cedar kernel: [ 3925.136213] [drm:drm_mode_debug_printmodeline], Modeline 23:"" 0 75010 1366 1399 1468 1553 768 772 784 805 0x0 0xa
Feb 10 22:19:20 cedar kernel: [ 3925.136225] [drm:drm_crtc_helper_set_mode], [CRTC:4]
Feb 10 22:19:20 cedar kernel: [ 3925.136240] [drm:cdv_intel_single_pipe_active], pipe enabled 0
Feb 10 22:19:20 cedar kernel: [ 3925.156108] [drm:cdv_intel_crtc_mode_set], Use SSC reference clock 100 Mhz
Feb 10 22:19:20 cedar kernel: [ 3925.156116] [drm:drm_mode_debug_printmodeline], Modeline 24:"" 0 75010 1366 1399 1468 1553 768 772 784 805 0x0 0xa
Feb 10 22:19:20 cedar kernel: [ 3925.161469] [drm:cdv_sb_write], 0x00008038: 0x0068a701 (before)
Feb 10 22:19:20 cedar kernel: [ 3925.161481] [drm:cdv_sb_write], 0x00008038: 0x0068a701
Feb 10 22:19:20 cedar kernel: [ 3925.177043] [drm:cdv_sb_write], 0x00008038: 0x0068a701 (after)
Feb 10 22:19:20 cedar kernel: [ 3925.185509] [drm:cdv_dpll_set_clock_cdv], use their DPLL for pipe A/B
Feb 10 22:19:20 cedar kernel: [ 3925.193539] [drm:cdv_sb_write], 0x00008030: 0x7e40221c (before)
Feb 10 22:19:20 cedar kernel: [ 3925.193572] [drm:cdv_sb_write], 0x00008030: 0x7e40221c
Feb 10 22:19:20 cedar kernel: [ 3925.209549] [drm:cdv_sb_write], 0x00008030: 0x7e40221c (after)
Feb 10 22:19:20 cedar kernel: [ 3925.225051] [drm:cdv_sb_write], 0x00008028: 0x3d00217f (before)
Feb 10 22:19:20 cedar kernel: [ 3925.225079] [drm:cdv_sb_write], 0x00008028: 0x3d00217f
Feb 10 22:19:20 cedar kernel: [ 3925.241569] [drm:cdv_sb_write], 0x00008028: 0x3d00217f (after)
Feb 10 22:19:20 cedar kernel: [ 3925.257235] [drm:cdv_sb_write], 0x00008034: 0x88000157 (before)
Feb 10 22:19:20 cedar kernel: [ 3925.257269] [drm:cdv_sb_write], 0x00008034: 0x88000157
Feb 10 22:19:20 cedar kernel: [ 3925.273569] [drm:cdv_sb_write], 0x00008034: 0x88000157 (after)
Feb 10 22:19:20 cedar kernel: [ 3925.289248] [drm:cdv_sb_write], 0x0000803c: 0x85553000 (before)
Feb 10 22:19:20 cedar kernel: [ 3925.289282] [drm:cdv_sb_write], 0x0000803c: 0x85553000
Feb 10 22:19:20 cedar kernel: [ 3925.305613] [drm:cdv_sb_write], 0x0000803c: 0x85553000 (after)
Feb 10 22:19:20 cedar kernel: [ 3925.305799] [drm:cdv_intel_crtc_mode_set], Mode for pipe B:
Feb 10 22:19:20 cedar kernel: [ 3925.305816] [drm:drm_mode_debug_printmodeline], Modeline 23:"" 0 75010 1366 1399 1468 1553 768 772 784 805 0x0 0xa
Feb 10 22:19:20 cedar kernel: [ 3925.345774] [drm:drm_crtc_helper_set_mode], [ENCODER:10:LVDS-10] set [MODE:23:]
Feb 10 22:19:20 cedar kernel: [ 3925.345981] [drm:cdv_intel_single_pipe_active], pipe enabled 2
Feb 10 22:19:20 cedar kernel: [ 3925.385793] [drm:drm_crtc_helper_set_config], Setting connector DPMS state to on
Feb 10 22:19:20 cedar kernel: [ 3925.385811] [drm:drm_crtc_helper_set_config], 	[CONNECTOR:9:LVDS-1] set DPMS on
Feb 10 22:19:20 cedar kernel: [ 3925.425558] [drm:cdv_intel_single_pipe_active], pipe enabled 2
Feb 10 22:19:20 cedar kernel: [ 3925.505061] [drm:cdv_intel_single_pipe_active], pipe enabled 2