On Fri, 2012-04-27 at 23:25 +0200, Daniel Vetter wrote: > Hm. Can you please install intel-gpu-tools and attach the output of > intel_reg_dumper? I have an idea ... Here it is with intel_backlight/brightness set to 1 ("strobe light" behavior occurring): PGETBL_CTL: 0x00000000 GEN6_INSTDONE_1: 0x8888fffb GEN6_INSTDONE_2: 0x03305e3f CPU_VGACNTRL: 0x80000000 (disabled) DIGITAL_PORT_HOTPLUG_CNTRL: 0x00000000 RR_HW_CTL: 0x00000000 (low 0, high 0) FDI_PLL_BIOS_0: 0xffffffff FDI_PLL_BIOS_1: 0xffffffff FDI_PLL_BIOS_2: 0xffffffff DISPLAY_PORT_PLL_BIOS_0: 0xffffffff DISPLAY_PORT_PLL_BIOS_1: 0xffffffff DISPLAY_PORT_PLL_BIOS_2: 0xffffffff FDI_PLL_FREQ_CTL: 0xffffffff PIPEACONF: 0xc0000050 (enabled, active, 6bpc) HTOTAL_A: 0x05d90555 (1366 active, 1498 total) HBLANK_A: 0x05d90555 (1366 start, 1498 end) HSYNC_A: 0x05a50585 (1414 start, 1446 end) VTOTAL_A: 0x031502ff (768 active, 790 total) VBLANK_A: 0x031502ff (768 start, 790 end) VSYNC_A: 0x03040300 (769 start, 773 end) VSYNCSHIFT_A: 0x00000000 PIPEASRC: 0x055502ff (1366, 768) PIPEA_DATA_M1: 0x7e1380e4 (TU 64, val 0x1380e4 1278180) PIPEA_DATA_N1: 0x0020f580 (val 0x20f580 2160000) PIPEA_DATA_M2: 0x00000000 (TU 1, val 0x0 0) PIPEA_DATA_N2: 0x00000000 (val 0x0 0) PIPEA_LINK_M1: 0x00011562 (val 0x11562 71010) PIPEA_LINK_N1: 0x00041eb0 (val 0x41eb0 270000) PIPEA_LINK_M2: 0x00000000 (val 0x0 0) PIPEA_LINK_N2: 0x00000000 (val 0x0 0) DSPACNTR: 0xd8004400 (enabled) DSPABASE: 0x00000000 DSPASTRIDE: 0x00001600 (88) DSPASURF: 0x009bf000 DSPATILEOFF: 0x00000000 (0, 0) PIPEBCONF: 0x00000000 (disabled, inactive, 8bpc) HTOTAL_B: 0x00000000 (1 active, 1 total) HBLANK_B: 0x00000000 (1 start, 1 end) HSYNC_B: 0x00000000 (1 start, 1 end) VTOTAL_B: 0x00000000 (1 active, 1 total) VBLANK_B: 0x00000000 (1 start, 1 end) VSYNC_B: 0x00000000 (1 start, 1 end) VSYNCSHIFT_B: 0x00000000 DSPBCNTR: 0x00004000 (disabled) DSPBBASE: 0x00000000 DSPBSTRIDE: 0x00000000 (0) DSPBSURF: 0x00000000 DSPBTILEOFF: 0x00000000 (0, 0) PIPEBSRC: 0x00000000 (1, 1) PIPEB_DATA_M1: 0x00000000 (TU 1, val 0x0 0) PIPEB_DATA_N1: 0x00000000 (val 0x0 0) PIPEB_DATA_M2: 0x00000000 (TU 1, val 0x0 0) PIPEB_DATA_N2: 0x00000000 (val 0x0 0) PIPEB_LINK_M1: 0x00000000 (val 0x0 0) PIPEB_LINK_N1: 0x00000000 (val 0x0 0) PIPEB_LINK_M2: 0x00000000 (val 0x0 0) PIPEB_LINK_N2: 0x00000000 (val 0x0 0) PFA_CTL_1: 0x00000000 (disable, auto_scale yes, auto_scale_cal no, v_filter enable, vadapt disable, mode least, filter_sel programmed,chroma pre-filter disable, vert3tap auto, v_inter_invert field 1) PFA_CTL_2: 0x00007e80 (vscale 0.988281) PFA_CTL_3: 0x00003f40 (vscale initial phase 0.494141) PFA_CTL_4: 0x00007d54 (hscale 0.979126) PFA_WIN_POS: 0x00000000 (0, 0) PFA_WIN_SIZE: 0x00000000 (0, 0) PFB_CTL_1: 0x00000000 (disable, auto_scale yes, auto_scale_cal no, v_filter enable, vadapt disable, mode least, filter_sel programmed,chroma pre-filter disable, vert3tap auto, v_inter_invert field 1) PFB_CTL_2: 0x00000000 (vscale 0.000000) PFB_CTL_3: 0x00000000 (vscale initial phase 0.000000) PFB_CTL_4: 0x00000000 (hscale 0.000000) PFB_WIN_POS: 0x00000000 (0, 0) PFB_WIN_SIZE: 0x00000000 (0, 0) PCH_DREF_CONTROL: 0x00001402 (cpu source disable, ssc_source enable, nonspread_source enable, superspread_source disable, ssc4_mode downspread, ssc1 enable, ssc4 disable) PCH_RAWCLK_FREQ: 0x0000007d (FDL_TP1 timer 0.5us, FDL_TP2 timer 1.5us, freq 125) PCH_DPLL_TMR_CFG: 0x0271186a PCH_SSC4_PARMS: 0x01204860 PCH_SSC4_AUX_PARMS: 0x000029c5 PCH_DPLL_SEL: 0x00000008 (TransA DPLL enable (DPLL A), TransB DPLL disable (DPLL (null))) PCH_DPLL_ANALOG_CTL: 0x00008000 PCH_DPLL_A: 0x88046004 (enable, sdvo high speed no, mode LVDS, p2 Div 14, FPA0 P1 3, FPA1 P1 3, refclk SSC, sdvo/hdmi mul 1) PCH_DPLL_B: 0x04800080 (disable, sdvo high speed no, mode (null), p2 (null), FPA0 P1 8, FPA1 P1 8, refclk default 120Mhz, sdvo/hdmi mul 1) PCH_FPA0: 0x00021007 (n = 2, m1 = 16, m2 = 7) PCH_FPA1: 0x00021007 (n = 2, m1 = 16, m2 = 7) PCH_FPB0: 0x00030d07 (n = 3, m1 = 13, m2 = 7) PCH_FPB1: 0x00030d07 (n = 3, m1 = 13, m2 = 7) TRANS_HTOTAL_A: 0x05d90555 (1366 active, 1498 total) TRANS_HBLANK_A: 0x05d90555 (1366 start, 1498 end) TRANS_HSYNC_A: 0x05a50585 (1414 start, 1446 end) TRANS_VTOTAL_A: 0x031502ff (768 active, 790 total) TRANS_VBLANK_A: 0x031502ff (768 start, 790 end) TRANS_VSYNC_A: 0x03040300 (769 start, 773 end) TRANS_VSYNCSHIFT_A: 0x00000000 TRANSA_DATA_M1: 0x00000000 (TU 1, val 0x0 0) TRANSA_DATA_N1: 0x00000000 (val 0x0 0) TRANSA_DATA_M2: 0x00000000 (TU 1, val 0x0 0) TRANSA_DATA_N2: 0x00000000 (val 0x0 0) TRANSA_DP_LINK_M1: 0x00000000 (val 0x0 0) TRANSA_DP_LINK_N1: 0x00000000 (val 0x0 0) TRANSA_DP_LINK_M2: 0x00000000 (val 0x0 0) TRANSA_DP_LINK_N2: 0x00000000 (val 0x0 0) TRANS_HTOTAL_B: 0x00000000 (1 active, 1 total) TRANS_HBLANK_B: 0x00000000 (1 start, 1 end) TRANS_HSYNC_B: 0x00000000 (1 start, 1 end) TRANS_VTOTAL_B: 0x00000000 (1 active, 1 total) TRANS_VBLANK_B: 0x00000000 (1 start, 1 end) TRANS_VSYNC_B: 0x00000000 (1 start, 1 end) TRANS_VSYNCSHIFT_B: 0x00000000 TRANSB_DATA_M1: 0x00000000 (TU 1, val 0x0 0) TRANSB_DATA_N1: 0x00000000 (val 0x0 0) TRANSB_DATA_M2: 0x00000000 (TU 1, val 0x0 0) TRANSB_DATA_N2: 0x00000000 (val 0x0 0) TRANSB_DP_LINK_M1: 0x00000000 (val 0x0 0) TRANSB_DP_LINK_N1: 0x00000000 (val 0x0 0) TRANSB_DP_LINK_M2: 0x00000000 (val 0x0 0) TRANSB_DP_LINK_N2: 0x00000000 (val 0x0 0) TRANS_HTOTAL_C: 0x00000000 (1 active, 1 total) TRANS_HBLANK_C: 0x00000000 (1 start, 1 end) TRANS_HSYNC_C: 0x00000000 (1 start, 1 end) TRANS_VTOTAL_C: 0x00000000 (1 active, 1 total) TRANS_VBLANK_C: 0x00000000 (1 start, 1 end) TRANS_VSYNC_C: 0x00000000 (1 start, 1 end) TRANS_VSYNCSHIFT_C: 0x00000000 TRANSC_DATA_M1: 0x00000000 (TU 1, val 0x0 0) TRANSC_DATA_N1: 0x00000000 (val 0x0 0) TRANSC_DATA_M2: 0x00000000 (TU 1, val 0x0 0) TRANSC_DATA_N2: 0x00000000 (val 0x0 0) TRANSC_DP_LINK_M1: 0x00000000 (val 0x0 0) TRANSC_DP_LINK_N1: 0x00000000 (val 0x0 0) TRANSC_DP_LINK_M2: 0x00000000 (val 0x0 0) TRANSC_DP_LINK_N2: 0x00000000 (val 0x0 0) TRANSACONF: 0xc0000000 (enable, active) TRANSBCONF: 0x00000000 (disable, inactive) TRANSCCONF: 0x00000000 (disable, inactive) FDI_TXA_CTL: 0xb0044000 (enable, train pattern not train, voltage swing 0.4V,pre-emphasis 0dB, port width X1, enhanced framing enable, FDI PLL enable, scrambing enable, master mode disable) FDI_TXB_CTL: 0x00040000 (disable, train pattern pattern_1, voltage swing 0.4V,pre-emphasis 0dB, port width X1, enhanced framing enable, FDI PLL disable, scrambing enable, master mode disable) FDI_TXC_CTL: 0x00000000 (disable, train pattern pattern_1, voltage swing 0.4V,pre-emphasis 0dB, port width X1, enhanced framing disable, FDI PLL disable, scrambing enable, master mode disable) FDI_RXA_CTL: 0x80022350 (enable, train pattern not train, port width X1, 6bpc,link_reverse_strap_overwrite no, dmi_link_reverse no, FDI PLL enable,FS ecc disable, FE ecc disable, FS err report enable, FE err report enable,scrambing enable, enhanced framing enable, PCDClk) FDI_RXB_CTL: 0x00000040 (disable, train pattern pattern_1, port width X1, 8bpc,link_reverse_strap_overwrite no, dmi_link_reverse no, FDI PLL disable,FS ecc disable, FE ecc disable, FS err report disable, FE err report disable,scrambing enable, enhanced framing enable, RawClk) FDI_RXC_CTL: 0x00000040 (disable, train pattern pattern_1, port width X1, 8bpc,link_reverse_strap_overwrite no, dmi_link_reverse no, FDI PLL disable,FS ecc disable, FE ecc disable, FS err report disable, FE err report disable,scrambing enable, enhanced framing enable, RawClk) FDI_RXA_MISC: 0x00000080 (FDI Delay 128) FDI_RXB_MISC: 0x00000080 (FDI Delay 128) FDI_RXC_MISC: 0x00000080 (FDI Delay 128) FDI_RXA_TUSIZE1: 0x7e000000 FDI_RXA_TUSIZE2: 0x7e000000 FDI_RXB_TUSIZE1: 0x7e000000 FDI_RXB_TUSIZE2: 0x7e000000 FDI_RXC_TUSIZE1: 0x7e000000 FDI_RXC_TUSIZE2: 0x7e000000 FDI_PLL_CTL_1: 0x7e000000 FDI_PLL_CTL_2: 0x7e000000 FDI_RXA_IIR: 0x00000000 FDI_RXA_IMR: 0x000008ff FDI_RXB_IIR: 0x00000000 FDI_RXB_IMR: 0x000008ff PCH_ADPA: 0x00f40000 (disabled, transcoder A, -hsync, -vsync) HDMIB: 0x00000018 (disabled pipe A 8bpc SDVO DVI audio disabled +vsync +hsync non-detected) HDMIC: 0x0000001c (disabled pipe A 8bpc SDVO DVI audio disabled +vsync +hsync detected) HDMID: 0x00000018 (disabled pipe A 8bpc SDVO DVI audio disabled +vsync +hsync non-detected) PCH_LVDS: 0x80200302 (enabled, pipe A, 18 bit, 1 channel) CPU_eDP_A: 0x00000018 PCH_DP_B: 0x00000000 PCH_DP_C: 0x00000004 PCH_DP_D: 0x00000000 TRANS_DP_CTL_A: 0x60000418 (disable port none 6bpc +vsync +hsync) TRANS_DP_CTL_B: 0x60000018 (disable port none 8bpc +vsync +hsync) TRANS_DP_CTL_C: 0x60000018 (disable port none 8bpc +vsync +hsync) BLC_PWM_CPU_CTL2: 0x80000000 BLC_PWM_CPU_CTL: 0x00000001 BLC_PWM_PCH_CTL1: 0x80000000 BLC_PWM_PCH_CTL2: 0x13120000 PCH_PP_STATUS: 0xc0000008 (on, ready, sequencing idle) PCH_PP_CONTROL: 0xabcd0003 (blacklight disabled, power down on reset, panel on) PCH_PP_ON_DELAYS: 0x025807d0 PCH_PP_OFF_DELAYS: 0x01f409c4 PCH_PP_DIVISOR: 0x00186905 PORT_DBG: 0x00000000 (HW DRRS off) RC6_RESIDENCY_TIME: 0x02fb9ec6 RC6p_RESIDENCY_TIME: 0x00000000 RC6pp_RESIDENCY_TIME: 0x00000000