Hi hpa, 於 五，2012-12-28 於 15:44 -0800，H. Peter Anvin 提到： > On 12/28/2012 12:49 PM, Matthew Garrett wrote: > > On Fri, 2012-12-28 at 12:40 -0800, H. Peter Anvin wrote: > > > >>> I suspect that what we *should* do looks like: > >>> > >>> 1. If ACPI exports a Time and Alarm Device (ACPI000E) the use it; > >>> 2. If ACPI exports an PC/AT device (PNP0B00/1/2) then use it(*); > >>> 3. If we have an EFI RTC use it; > >>> 4. Probe for a PC/AT RTC device. > > > > In terms of ordering, 3 should probably come before 2 - but that depends > > on us actually fixing the issues that are preventing some of these calls > > from working. As far as wallclock time goes, EFI is going to be > > available to us before we've parsed the DSDT to determine whether > > there's any ACPI devices, so we'll almost certainly end up having to use > > it at at least some point during boot. Otherwise, agreed. > > > > [Resending due to misconfigured tablet] > > 3 before 2 is exactly what is known to break on existing hardware (ASUS). I didn't find the EFI RTC problem on Asus from google. Could you please share what's the situation on ASUS hardware? Thanks a lot! Joey Lee > > If anything, we should move to using the EFI RTC as a very last resort, > i.e. 3 after 4. Ideally we should match Win8 behavior, but that would > require someone mocking up different ACPI and EFI functions in a > simulator and see how Win8 prioritizes things. > > -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 > -- 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
