於 三,2012-10-03 於 08:26 -0400,Dan 提到: > >> Acpidump is attached. > >> > > > > I traced your DSDT at this morning, didn't see problem in _BCL, _BCM > and > > _BQC. > > Per DSDT, the _BQC on this machine used brightness value but not > index, > > so 'video.use_bios_initial_backlight=0' should works to you for set > the > > backlight to max_level when acpi/video driver loaded. > > > > And, the value of max_level in package of _BCL is 100, there have no > 0 > > value in level list: > > > > Method (_BCL, 0, NotSerialized) > > { > > Return (Package (0x0C) > > { > > 0x46, /* level on AC */ > > 0x28, /* level on Battery */ > > 0x0A, /* 10 */ > > 0x14, /* 20 */ > > 0x1E, > > 0x28, > > 0x32, > > 0x3C, > > 0x46, > > 0x50, > > 0x5A, > > 0x64 /* 100 */ > > > > That strange for 'video.use_bios_initial_backlight=0' doesn't work > to > > you for set the backlight level to maximum. > > Could you please share the acpi debug log? Please add the following > > kernel parameter when system boot. Please also check the kernel > config > > need CONFIG_ACPI_DEBUG=y: > > > > acpi.debug_level=0x0000000F acpi.debug_layer=0xffffffff > log_buf_len=5M > > > > Please attached on your dmesg or boot message after system boot > finished. Hope we > > can find any hint from acpi debug log. > > > > > > Thanks a lot! > > Joey Lee > > > > I've attached the resulting dmesg log. I also set the loglevel to 8 > during this so I could watch the messages on the console. The last > message I could see before the backlight went out was at 5.93 seconds. > I tried looking through the log around there, but it's over my head. > > Thank you, > Dan > Thanks for your acpi debug log. Per acpi debug log, the DD02 device have backlight control capability. The default brightness value is 30, acpi/video driver set brightness value to 100 then set it back to 30 for determine does _BQC use index but not brightness level: [ 3.113825] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BCL] (Node ffff88007b741c58) [ 3.115980] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BQC] (Node ffff88007b741ca8) [ 3.118310] exregion-0302 [00] ex_system_io_space_han: System-IO (width 32) R/W 1 Address=0000000000000080 [ 3.220145] utils-0286 [00] evaluate_integer : Return value [30] <=== default brightness value is 30(default value set by BIOS) [ 3.222315] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BCM] (Node ffff88007b741c80) [ 3.225422] exregion-0302 [00] ex_system_io_space_han: System-IO (width 8) R/W 1 Address=0000000000000072 [ 3.227947] exregion-0302 [00] ex_system_io_space_han: System-IO (width 8) R/W 1 Address=0000000000000073 [ 3.230424] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BQC] (Node ffff88007b741ca8) [ 3.233123] exregion-0302 [00] ex_system_io_space_han: System-IO (width 32) R/W 1 Address=0000000000000080 [ 3.333487] utils-0286 [00] evaluate_integer : Return value [100] <=== set to 100 for determine _BQC_use_index [ 3.336019] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BCM] (Node ffff88007b741c80) [ 3.339263] exregion-0302 [00] ex_system_io_space_han: System-IO (width 8) R/W 1 Address=0000000000000072 [ 3.342167] exregion-0302 [00] ex_system_io_space_han: System-IO (width 8) R/W 1 Address=0000000000000073 [ 3.345001] video-0734 [00] video_init_brightness : found 10 brightness levels [ 3.347899] utils-0286 [00] evaluate_integer : Return value [131072] [ 3.350956] ACPI: Execute Method [\_SB_.PCI0.OVGA.DD02._BQC] (Node ffff88007b741ca8) [ 3.354598] exregion-0302 [00] ex_system_io_space_han: System-IO (width 32) R/W 1 Address=0000000000000080 [ 3.456824] utils-0286 [00] evaluate_integer : Return value [30] <=== set brightness value back to 30 [ 3.460059] acpi device:28: registered as cooling_device0 The above acpi/video's behavior is normal, didn't see strange thing. Please add 'video.use_bios_initial_backlight=0' then grab acpi debug log again. You can find the similar log of DD02 device, this time the latest 'Return value' should be 100 like: Return value [100]. If 'video.use_bios_initial_backlight=0' works fine, the brightness should set to 100%, means lightest. Another dubious message in your dmesg is not from ACPI, it's a message from i915 driver: [ 2.083603] i915: fixme: max PWM is zero That means ODM set PWM register value default to zero, this register used to control the the intensity of the backlight. I am still looking what's the side effect that was caused by 'PWM = 0'. Thanks a lot! Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html