
support at ocg
Sep 7, 2007, 6:06 AM
Post #3 of 11
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Re: Real Time Clock Alarm Broken with 2.6.22+ kernel
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Craig, I wrote an nvram-wakeup replacement call acpi-wakeup. It is a bash script that is command line compatible with nvram-wakeup, but uses the proc acpi interface and handles epoch data etc. The acpi path is just a constant you can change. It would need a tweak to work for you situation, but your welcome to play with it. I can put it on www.generationd.com if you want it. MD _____ From: mythtv-users-bounces [at] mythtv [mailto:mythtv-users-bounces [at] mythtv] On Behalf Of Craig Huff Sent: Friday, September 07, 2007 8:56 AM To: mythtv-users [at] mythtv Subject: [mythtv-users] Real Time Clock Alarm Broken with 2.6.22+ kernel Hi, all For your information: I had done a lot of work to figure out how to get the RTC alarm to work in FC6 on my system so MythTV can wake from Suspend-to-disk/Power Off to do mythfilldatabase jobs and to wake in time to record scheduled programs. I upgraded everything last week when I needed to move MythTV up to the latest version to switch over to SchedulesDirect for collecting TV schedule data. I posted a message on the atrpms list when I discovered that my system wasn't waking up anymore and found that /proc/acpi/alarm didn't exist. A kind soul (apparently a kindred MythTV user) replied with a pointer to the updated wiki page: http://www.mythtv.org/wiki/index.php/ACPI_Wakeup <http://www.mythtv.org/wiki/index.php/ACPI_Wakeup> which has had an update about the change the kernel gurus did, changing the path to the alarm to be /sys/class/rtc/rtc0/wakealarm. While they were at it, they changed the format of the value from the former, human-readable string to the seconds since the "epoch" (see man-page regarding "date +%s"). Oh, and they changed the code behind it so that to change the alarm you have to first reset it, which can be done (amongst other ways) by "echo 0 > /sys/class/rtc/rtc0/wakealarm". Finally, don't expect the value you get back to equal the value you put in to the alarm unless your mobo is (in my experience) the rare bird that REALLY takes the WHOLE alarm setting, including month and year. You're more likely to see "echo 12345 > /sys/class/rtc/rtc0/wakealarm; cat /sys/class/rtc/rtc0/wakealarm" return a value like 87654399899 (made up number on my part). From googling, it appears that this will be the original value plus a TBD constant that depends on your mobo. YMMV. However... On my system, the code changes behind the new design have broken the alarm function completely. I have tried disabling the hwclock update in /etc/init.d/halt, turned on all the elements in /proc/acpi/wakeup, and enabled on the (old technology) APM alarm in the BIOS, all to no avail. If some kind soul has gotten further with this "improvement" and can give me any ideas how to fix this, short of regressing to a kernel < 2.6.22, I would appreciate it. AAAAUUUUGGGHHHH!!!!! Craig. P.S. If I forgot to mention some detail of relevance, please remind me to reply with the appropriate data.
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