On 12/19/2013 07:54 PM, joeyli wrote: > Hi hpa, > > 於 四，2013-12-19 於 06:38 -0800，H. Peter Anvin 提到： >> Where did you find a platform with "no CMOS" set and a PNP RTC? I find the expect behavior in that case to be quite ambiguous and it is not at all clear to me that what you have here is the right thing. > > Actually there doesn't have the box both with "No CMOS" and PNP device. > I choice to totally block rtc-cmos driver when "No CMOS RTC" because the > definition in ACPI spec: > > CMOS RTC Not Present > > If set, indicates that the CMOS RTC is either not implemented, or > does not exist at the legacy addresses. OSPM uses the Control > Method Time and Alarm Namespace device instead. > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > It suggest us using ACPI TAD interface when this flag present. But, I > agreed your point for this is ambiguous due to ACPI spec didn't clear > define the relationship between PNP0B0x. > > Maybe we can do more detail check in cmos_init when "No CMOS RTC" set: > + check if have ACPI TAD device, then block rtc-cmos > + check if no ACPI TAD device, but have PNP0B0x, then we use PNP0b0x. > I think the only thing we should use that bit for is to inhibit the last-resort probing of I/O ports 0x70-0x73... if at all. -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
