>Here are the dsdt decompiled, and the acpidump output. >Could you see also the section related to brightness control? I can Yes, I found : Method (_L02,..) If (LEqual (Local0, 0x03)) { Notify (\_SB.C002.C080.C13F, 0x87) } If (LEqual (Local0, 0x02)) { Notify (\_SB.C002.C080.C13F, 0x86) } And: _BCL, _BCM under C13F. But there is NO _BQC. Instead of _BQC, there do have a _BCQ in DSDT. Is this a bug of BIOS? Acpi video drvier needs _BQC to get the current brightness level, and to get the next level to set on receiving notification of 0x86 (Increase Brightness) , 0x87 (decrease Brightness). Could you just try to replace _BQC with _BCQ in acpi/video.c? Thanks, Luming - 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