Today i was installed gentoo on my laptop .
I've noticed an error from dmesg output that gentoo canot enable ASPM:
when i type this : dmesg | grep failed
get :[ 0.292525] pci0000:3f: ACPI _OSC support notification failed, disabling PCIe ASPM
I was very appreciate to who can tell me the right to enable kernel correct and enable ASPM support for my kernel .the reason being that it should increase battery life.it's abug or my kerner configure didn't get it?my kernel configure
about ASPM :
CONFIG_PCIEASPM=y
# CONFIG_PCIEASPM_DEBUG is not set
# CONFIG_PCIEASPM_DEFAULT is not set
CONFIG_PCIEASPM_POWERSAVE=y
# CONFIG_PCIEASPM_PERFORMANCE is not set
and ACPI options :
# Power management and ACPI options
CONFIG_ACPI=y
CONFIG_ACPI_SLEEP=y
CONFIG_ACPI_PROCFS=y
# CONFIG_ACPI_PROCFS_POWER is not set
# CONFIG_ACPI_EC_DEBUGFS is not set
CONFIG_ACPI_PROC_EVENT=y
CONFIG_ACPI_AC=y
CONFIG_ACPI_BATTERY=y
CONFIG_ACPI_BUTTON=y
CONFIG_ACPI_VIDEO=y
CONFIG_ACPI_FAN=y
CONFIG_ACPI_DOCK=y
CONFIG_ACPI_PROCESSOR=y
CONFIG_ACPI_HOTPLUG_CPU=y
# CONFIG_ACPI_PROCESSOR_AGGREGATOR is not set
CONFIG_ACPI_THERMAL=y
# CONFIG_ACPI_CUSTOM_DSDT is not set
CONFIG_ACPI_BLACKLIST_YEAR=0
# CONFIG_ACPI_DEBUG is not set
# CONFIG_ACPI_PCI_SLOT is not set
CONFIG_ACPI_CONTAINER=y
# CONFIG_ACPI_SBS is not set
# CONFIG_ACPI_HED is not set
# CONFIG_ACPI_CUSTOM_METHOD is not set
# CONFIG_ACPI_BGRT is not set
# CONFIG_ACPI_APEI is not set
CONFIG_X86_ACPI_CPUFREQ=y
CONFIG_X86_ACPI_CPUFREQ_CPB=y
# CONFIG_HOTPLUG_PCI_ACPI is not set
CONFIG_PNPACPI=y
CONFIG_ATA_ACPI=y
# CONFIG_PATA_ACPI is not set
# ACPI drivers
# ACPI drivers
# CONFIG_SENSORS_ACPI_POWER is not set
# CONFIG_THINKPAD_ACPI is not set
CONFIG_ACPI_WMI=y
# CONFIG_ACPI_TOSHIBA is not set
# CONFIG_ACPI_CMPC is not set

This sounds like kernel has queried the hardware and ASPM is disabled or not supported in the hardware. You can try and force it by passing pcie_aspm=force to your kernel but don't hold your breath.