It is a regression I never noticed this problem before.
I booted with drm.debug=0xe, this is what I found in /var/log/messages after rebooting.
Mar 22 12:10:03 slick kernel: [ 1779.451669] [drm:i965_update_wm], self-refresh entries: 80, wm: 432
Mar 22 12:10:03 slick kernel: [ 1779.451678] [drm:i965_update_wm], self-refresh watermark: display plane 432 cursor 32
Mar 22 12:10:03 slick kernel: [ 1779.451684] [drm:i965_update_wm], Setting FIFO watermarks - A: 8, B: 8, C: 8, SR 432
Mar 22 12:10:03 slick kernel: [ 1779.470145] [drm:intel_update_fbc], fbc set to per-chip default
Mar 22 12:10:03 slick kernel: [ 1779.470152] [drm:intel_update_fbc], fbc disabled per module param
Mar 22 12:10:03 slick kernel: [ 1779.472097] [drm:intel_panel_actually_set_backlight], set backlight PWM = 1
Mar 22 12:10:03 slick kernel: [ 1779.472120] [drm:intel_opregion_asle_intr], non asle set request??
Mar 22 12:10:03 slick kernel: [ 1779.472133] [drm:intel_connector_check_state], [CONNECTOR:5:LVDS-1]
Mar 22 12:10:03 slick kernel: [ 1779.472141] [drm:intel_modeset_check_state], [ENCODER:6:LVDS-6]
Mar 22 12:10:03 slick kernel: [ 1779.472147] [drm:intel_modeset_check_state], [ENCODER:12:DAC-12]
Mar 22 12:10:03 slick kernel: [ 1779.472153] [drm:intel_modeset_check_state], [CRTC:3]
Mar 22 12:10:03 slick kernel: [ 1779.472158] [drm:intel_modeset_check_state], [CRTC:4]
Mar 22 12:15:25 slick kernel: [ 2100.982771] [drm:i915_driver_open],
// The screen turned black here
Mar 22 12:17:18 slick kernel: [ 2214.212056] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Mar 22 12:17:18 slick kernel: [ 2214.212102] [drm:i915_error_work_func], resetting chip
Mar 22 12:17:18 slick kernel: [ 2214.276527] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:18 slick kernel: [ 2214.336027] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:18 slick kernel: [ 2214.336032] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:18 slick kernel: [ 2214.336510] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:18 slick kernel: [ 2214.344038] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:18 slick kernel: [ 2214.344042] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:18 slick kernel: [ 2214.714043] [drm:i915_reset] *ERROR* Failed to reset chip.
Mar 22 12:17:32 slick kernel: [ 2228.850292] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:32 slick kernel: [ 2228.850299] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:32 slick kernel: [ 2228.850315] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:32 slick kernel: [ 2228.850319] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:32 slick kernel: [ 2228.850325] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:32 slick kernel: [ 2228.850529] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:32 slick kernel: [ 2228.850533] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:32 slick kernel: [ 2228.850539] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:32 slick kernel: [ 2228.858031] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:32 slick kernel: [ 2228.858038] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:32 slick kernel: [ 2228.858043] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:32 slick kernel: [ 2228.858058] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:32 slick kernel: [ 2228.858062] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:32 slick kernel: [ 2228.858067] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:32 slick kernel: [ 2228.866944] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:32 slick kernel: [ 2228.866950] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:32 slick kernel: [ 2228.866956] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2228.894501] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2228.894508] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:33 slick kernel: [ 2228.894523] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:33 slick kernel: [ 2228.894526] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:33 slick kernel: [ 2228.894533] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2228.894732] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:33 slick kernel: [ 2228.894737] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:33 slick kernel: [ 2228.894742] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:33 slick kernel: [ 2228.902022] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:33 slick kernel: [ 2228.902026] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:33 slick kernel: [ 2228.902029] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2228.902035] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:33 slick kernel: [ 2228.902038] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:33 slick kernel: [ 2228.902042] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:33 slick kernel: [ 2228.910023] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:33 slick kernel: [ 2228.910028] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:33 slick kernel: [ 2228.910033] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2229.020652] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2229.020660] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:33 slick kernel: [ 2229.020678] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:33 slick kernel: [ 2229.020681] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:33 slick kernel: [ 2229.020688] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:10:03 slick kernel: [ 1779.451669] [drm:i965_update_wm], self-refresh entries: 80, wm: 432
Mar 22 12:10:03 slick kernel: [ 1779.451678] [drm:i965_update_wm], self-refresh watermark: display plane 432 cursor 32
Mar 22 12:10:03 slick kernel: [ 1779.451684] [drm:i965_update_wm], Setting FIFO watermarks - A: 8, B: 8, C: 8, SR 432
Mar 22 12:10:03 slick kernel: [ 1779.470145] [drm:intel_update_fbc], fbc set to per-chip default
Mar 22 12:10:03 slick kernel: [ 1779.470152] [drm:intel_update_fbc], fbc disabled per module param
Mar 22 12:10:03 slick kernel: [ 1779.472097] [drm:intel_panel_actually_set_backlight], set backlight PWM = 1
Mar 22 12:10:03 slick kernel: [ 1779.472120] [drm:intel_opregion_asle_intr], non asle set request??
Mar 22 12:10:03 slick kernel: [ 1779.472133] [drm:intel_connector_check_state], [CONNECTOR:5:LVDS-1]
Mar 22 12:10:03 slick kernel: [ 1779.472141] [drm:intel_modeset_check_state], [ENCODER:6:LVDS-6]
Mar 22 12:10:03 slick kernel: [ 1779.472147] [drm:intel_modeset_check_state], [ENCODER:12:DAC-12]
Mar 22 12:10:03 slick kernel: [ 1779.472153] [drm:intel_modeset_check_state], [CRTC:3]
Mar 22 12:10:03 slick kernel: [ 1779.472158] [drm:intel_modeset_check_state], [CRTC:4]
Mar 22 12:15:25 slick kernel: [ 2100.982771] [drm:i915_driver_open],
// The screen turned black here
Mar 22 12:17:18 slick kernel: [ 2214.212056] [drm:i915_hangcheck_hung] *ERROR* Hangcheck timer elapsed... GPU hung
Mar 22 12:17:18 slick kernel: [ 2214.212102] [drm:i915_error_work_func], resetting chip
Mar 22 12:17:18 slick kernel: [ 2214.276527] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:18 slick kernel: [ 2214.336027] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:18 slick kernel: [ 2214.336032] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:18 slick kernel: [ 2214.336510] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:18 slick kernel: [ 2214.344038] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:18 slick kernel: [ 2214.344042] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:18 slick kernel: [ 2214.714043] [drm:i915_reset] *ERROR* Failed to reset chip.
Mar 22 12:17:32 slick kernel: [ 2228.850292] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:32 slick kernel: [ 2228.850299] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:32 slick kernel: [ 2228.850315] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:32 slick kernel: [ 2228.850319] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:32 slick kernel: [ 2228.850325] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:32 slick kernel: [ 2228.850529] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:32 slick kernel: [ 2228.850533] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:32 slick kernel: [ 2228.850539] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:32 slick kernel: [ 2228.858031] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:32 slick kernel: [ 2228.858038] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:32 slick kernel: [ 2228.858043] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:32 slick kernel: [ 2228.858058] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:32 slick kernel: [ 2228.858062] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:32 slick kernel: [ 2228.858067] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:32 slick kernel: [ 2228.866944] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:32 slick kernel: [ 2228.866950] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:32 slick kernel: [ 2228.866956] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2228.894501] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2228.894508] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:33 slick kernel: [ 2228.894523] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:33 slick kernel: [ 2228.894526] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:33 slick kernel: [ 2228.894533] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2228.894732] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:33 slick kernel: [ 2228.894737] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:33 slick kernel: [ 2228.894742] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:33 slick kernel: [ 2228.902022] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:33 slick kernel: [ 2228.902026] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:33 slick kernel: [ 2228.902029] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2228.902035] [drm:drm_mode_getconnector], [CONNECTOR:11:?]
Mar 22 12:17:33 slick kernel: [ 2228.902038] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1]
Mar 22 12:17:33 slick kernel: [ 2228.902042] [drm:intel_crt_detect], CRT not detected via hotplug
Mar 22 12:17:33 slick kernel: [ 2228.910023] [drm:drm_do_probe_ddc_edid], drm: skipping non-existent adapter i915 gmbus vga
Mar 22 12:17:33 slick kernel: [ 2228.910028] [drm:intel_crt_detect_ddc], CRT not detected via DDC:0x50 [no valid EDID found]
Mar 22 12:17:33 slick kernel: [ 2228.910033] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:11:VGA-1] disconnected
Mar 22 12:17:33 slick kernel: [ 2229.020652] [drm:drm_mode_getconnector], [CONNECTOR:5:?]
Mar 22 12:17:33 slick kernel: [ 2229.020660] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1]
Mar 22 12:17:33 slick kernel: [ 2229.020678] [drm:drm_helper_probe_single_connector_modes], [CONNECTOR:5:LVDS-1] probed modes :
Mar 22 12:17:33 slick kernel: [ 2229.020681] [drm:drm_mode_debug_printmodeline], Modeline 13:"1280x800" 60 71110 1280 1328 1360 1440 800 803 809 823 0x48 0xa
Mar 22 12:17:33 slick kernel: [ 2229.020688] [drm:drm_mode_getconnector], [CONNECTOR:5:?]