3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Lv Zheng <lv.zheng@xxxxxxxxx> [ Upstream commit 861ba6351c520328e94a78c923b415faa9116287 ] ACPICA commit 99bc3beca92c6574ea1d69de42e54f872e6373ce It is reported that on Linux, RTC driver complains wrong errors on hardware reduced platform: [ 4.085420] ACPI Warning: Could not enable fixed event - real_time_clock (4) (20160422/evxface-654) This patch fixes this by correctly adding runtime reduced hardware check. Reported by Chandan Tagore, fixed by Lv Zheng. Link: https://github.com/acpica/acpica/commit/99bc3bec Tested-by: Chandan Tagore <tagore.chandan@xxxxxxxxx> Signed-off-by: Lv Zheng <lv.zheng@xxxxxxxxx> Signed-off-by: Bob Moore <robert.moore@xxxxxxxxx> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/acpi/acpica/evxfevnt.c | 18 ++++++++++++++++++ 1 file changed, 18 insertions(+) --- a/drivers/acpi/acpica/evxfevnt.c +++ b/drivers/acpi/acpica/evxfevnt.c @@ -180,6 +180,12 @@ acpi_status acpi_enable_event(u32 event, ACPI_FUNCTION_TRACE(acpi_enable_event); + /* If Hardware Reduced flag is set, there are no fixed events */ + + if (acpi_gbl_reduced_hardware) { + return_ACPI_STATUS(AE_OK); + } + /* Decode the Fixed Event */ if (event > ACPI_EVENT_MAX) { @@ -237,6 +243,12 @@ acpi_status acpi_disable_event(u32 event ACPI_FUNCTION_TRACE(acpi_disable_event); + /* If Hardware Reduced flag is set, there are no fixed events */ + + if (acpi_gbl_reduced_hardware) { + return_ACPI_STATUS(AE_OK); + } + /* Decode the Fixed Event */ if (event > ACPI_EVENT_MAX) { @@ -290,6 +302,12 @@ acpi_status acpi_clear_event(u32 event) ACPI_FUNCTION_TRACE(acpi_clear_event); + /* If Hardware Reduced flag is set, there are no fixed events */ + + if (acpi_gbl_reduced_hardware) { + return_ACPI_STATUS(AE_OK); + } + /* Decode the Fixed Event */ if (event > ACPI_EVENT_MAX) {