2.6.27-stable review patch. If anyone has any objections, please let us know. ------------------ From: Bjorn Helgaas commit 758a7f7bb86b520aadc484f23da85e547b3bf3d8 upstream x86: register a platform RTC device if PNP doesn't describe it Most if not all x86 platforms have an RTC device, but sometimes the RTC is not exposed as a PNP0b00/PNP0b01/PNP0b02 device in PNPBIOS or ACPI: http://bugzilla.kernel.org/show_bug.cgi?id=11580 https://bugzilla.redhat.com/show_bug.cgi?id=451188 It's best if we can discover the RTC via PNP because then we know which flavor of device it is, where it lives, and which IRQ it uses. But if we can't, we should register a platform device using the compiled-in RTC_PORT/RTC_IRQ resource assumptions. Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki Acked-by: David Brownell Reported-by: Rik Theys Reported-by: shr_msn@yahoo.com.tw Cc: Chuck Ebbert Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/rtc.c | 22 ++++++++++++++++++---- 1 file changed, 18 insertions(+), 4 deletions(-) --- a/arch/x86/kernel/rtc.c +++ b/arch/x86/kernel/rtc.c @@ -223,11 +223,25 @@ static struct platform_device rtc_device static __init int add_rtc_cmos(void) { #ifdef CONFIG_PNP - if (!pnp_platform_devices) - platform_device_register(&rtc_device); -#else + static const char *ids[] __initconst = + { "PNP0b00", "PNP0b01", "PNP0b02", }; + struct pnp_dev *dev; + struct pnp_id *id; + int i; + + pnp_for_each_dev(dev) { + for (id = dev->id; id; id = id->next) { + for (i = 0; i < ARRAY_SIZE(ids); i++) { + if (compare_pnp_id(id, ids[i]) != 0) + return 0; + } + } + } +#endif + platform_device_register(&rtc_device); -#endif /* CONFIG_PNP */ + dev_info(&rtc_device.dev, + "registered platform RTC device (no PNP device found)\n"); return 0; } device_initcall(add_rtc_cmos); --