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authorJan Beulich <JBeulich@suse.com>2013-10-21 09:31:57 +0100
committerIngo Molnar <mingo@kernel.org>2013-10-26 13:36:00 +0200
commitee5872befc9324fa4c2583c24d7ee7120314a2b7 (patch)
treebbefc0fd674f62c181fa2d05a91f966ca4794da1 /arch/x86/kernel/rtc.c
parent77748e6315774025524e1f29431f4e3375d55b0d (diff)
downloadlinux-ee5872befc9324fa4c2583c24d7ee7120314a2b7.tar.bz2
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 <jbeulich@suse.com> Cc: John Stultz <john.stultz@linaro.org> Link: http://lkml.kernel.org/r/5265029D02000078000FC4D2@nat28.tlf.novell.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/kernel/rtc.c')
-rw-r--r--arch/x86/kernel/rtc.c8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/x86/kernel/rtc.c b/arch/x86/kernel/rtc.c
index 0aa29394ed6f..5b9dd445eb89 100644
--- a/arch/x86/kernel/rtc.c
+++ b/arch/x86/kernel/rtc.c
@@ -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");