Also when 'asus_laptop' driver is used with 3.0-2-generic 'oneiric' kernel I got ACPI exceptions when changing backlight level:
Jun 28 11:54:39 localhost kernel: [ 612.337945] ACPI Error: Result stack is empty! State=ffff880103c9ec00 (20110413/dswstate-98) Jun 28 11:54:39 localhost kernel: [ 612.337963] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110413/dsutils-646) Jun 28 11:54:39 localhost kernel: [ 612.337975] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110413/dsutils-763) Jun 28 11:54:39 localhost kernel: [ 612.337987] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.DWBL] (Node ffff880138e38578), AE_AML_NO_RETURN_VALUE (20110413/psparse-536) Jun 28 11:54:39 localhost kernel: [ 612.338009] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0E] (Node ffff880138e3fca8), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)
Jun 28 11:54:42 localhost kernel: [ 615.157385] ACPI Error: Result stack is empty! State=ffff880103c9f400 (20110413/dswstate-98) Jun 28 11:54:42 localhost kernel: [ 615.157403] ACPI Exception: AE_AML_NO_RETURN_VALUE, Missing or null operand (20110413/dsutils-646) Jun 28 11:54:42 localhost kernel: [ 615.157415] ACPI Exception: AE_AML_NO_RETURN_VALUE, While creating Arg 1 (20110413/dsutils-763) Jun 28 11:54:42 localhost kernel: [ 615.157428] ACPI Error: Method parse/execution failed [\_SB_.PCI0.VGA_.UPBL] (Node ffff880138e38550), AE_AML_NO_RETURN_VALUE (20110413/psparse-536) Jun 28 11:54:42 localhost kernel: [ 615.157450] ACPI Error: Method parse/execution failed [\_SB_.PCI0.SBRG.EC0_._Q0F] (Node ffff880138e3fcd0), AE_AML_NO_RETURN_VALUE (20110413/psparse-536)
No such messages when intel_backlight is used.
Also when 'asus_laptop' driver is used with 3.0-2-generic 'oneiric' kernel I got ACPI exceptions when changing backlight level:
Jun 28 11:54:39 localhost kernel: [ 612.337945] ACPI Error: Result stack is empty! State=ffff88010 3c9ec00 (20110413/ dswstate- 98) NO_RETURN_ VALUE, Missing or null operand (20110413/ dsutils- 646) NO_RETURN_ VALUE, While creating Arg 1 (20110413/ dsutils- 763) PCI0.VGA_ .DWBL] (Node ffff880138e38578), AE_AML_ NO_RETURN_ VALUE (20110413/ psparse- 536) PCI0.SBRG. EC0_._Q0E] (Node ffff880138e3fca8), AE_AML_ NO_RETURN_ VALUE (20110413/ psparse- 536)
Jun 28 11:54:39 localhost kernel: [ 612.337963] ACPI Exception: AE_AML_
Jun 28 11:54:39 localhost kernel: [ 612.337975] ACPI Exception: AE_AML_
Jun 28 11:54:39 localhost kernel: [ 612.337987] ACPI Error: Method parse/execution failed [\_SB_.
Jun 28 11:54:39 localhost kernel: [ 612.338009] ACPI Error: Method parse/execution failed [\_SB_.
Jun 28 11:54:42 localhost kernel: [ 615.157385] ACPI Error: Result stack is empty! State=ffff88010 3c9f400 (20110413/ dswstate- 98) NO_RETURN_ VALUE, Missing or null operand (20110413/ dsutils- 646) NO_RETURN_ VALUE, While creating Arg 1 (20110413/ dsutils- 763) PCI0.VGA_ .UPBL] (Node ffff880138e38550), AE_AML_ NO_RETURN_ VALUE (20110413/ psparse- 536) PCI0.SBRG. EC0_._Q0F] (Node ffff880138e3fcd0), AE_AML_ NO_RETURN_ VALUE (20110413/ psparse- 536)
Jun 28 11:54:42 localhost kernel: [ 615.157403] ACPI Exception: AE_AML_
Jun 28 11:54:42 localhost kernel: [ 615.157415] ACPI Exception: AE_AML_
Jun 28 11:54:42 localhost kernel: [ 615.157428] ACPI Error: Method parse/execution failed [\_SB_.
Jun 28 11:54:42 localhost kernel: [ 615.157450] ACPI Error: Method parse/execution failed [\_SB_.
No such messages when intel_backlight is used.