On Sun, Jan 07, 2007 at 06:31:17PM -0800, David Brownell wrote: > On Saturday 06 January 2007 9:57 pm, Matthew Garrett wrote: > > Especially since /proc/acpi/alarm is just banging on the RTC registers > > - the only ACPI thing about it is that the FADT can expose whether or > > not the extended registers exist, and then making sure that the GPE is > > enabled. > > The FADT also exposes whether the RTC can wake from S4. You may have > noticed that my rtc-cmos patch #3 exported the relevant FADT info > to the RTC device using platform_data, but the S4 wake capability flag > isn't useful for anything on today's Linux. Isn't useful in what way? It'd be helpful for userspace to know that now that we're actually using S4 for swsusp, but I understand that it might not fit into the current API terribly well. > Not speaking as an ACPI expert, I do see the ACPI spec says (right > under fig 4-11 in my version) that RTC events don't require GPEs. Hmm. My interpretation of that section had been that RTC_EN and RTC_STS were optional, and that a GPE would be required if they weren't implemented. On re-reading it, I think you're right. -- Matthew Garrett | mjg59 at srcf.ucam.org
