x86/time: Honor ACPI FADT flag indicating absence of a CMOS RTC

Even though the omission was found only during code review
(originally in the Xen hypervisor, looking through ACPI v5 flags
and their meanings and uses), we shouldn't be creating a
corresponding platform device in that case.

Signed-off-by: Jan Beulich <[email protected]>
Cc: John Stultz <[email protected]>
Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Ingo Molnar <[email protected]>
This commit is contained in:
Jan Beulich 2013-10-21 09:31:57 +01:00 • committed by Ingo Molnar
commit ee5872befc

View file

@ -192,6 +192,14 @@ static __init int add_rtc_cmos(void)
if (mrst_identify_cpu())
return -ENODEV;
#ifdef CONFIG_ACPI
if (acpi_gbl_FADT.boot_flags & ACPI_FADT_NO_CMOS_RTC) {
/* This warning can likely go away again in a year or two. */
pr_info("ACPI: not registering RTC platform device\n");
return -ENODEV;
}
#endif
platform_device_register(&rtc_device);
dev_info(&rtc_device.dev,
"registered platform RTC device (no PNP device found)\n");