Hi Thomas, 於 二，2010-03-30 於 17:31 +0100，Thomas Renninger 提到： > On Tuesday 30 March 2010 18:12:40 Joey Lee wrote: > > Hi Thomas, > > > > 於 二，2010-03-30 於 10:23 +0100，Thomas Renninger 提到： > > > Hi, > ... > > > Comments? > > > What userspace tools are candidates to implement this if this > > > makes sense? > > > > > > > HAL + pm-util or DeviceKit-power might the candidates. But, if there > > have no those component in userland, what will acpi thermal module do? > > Direct shutdown? > > And, how can kernel space know userland can do this job well? Might wait > > 10 seconds if system doesn't S4 or shutdown? > Yep, my idea is to e.g. provide: > /sys/class/thermal/S4_capable > By default you get: > cat /sys/class/thermal/S4_capable > 0 > and the thermal driver will call the same shutdown method > if the hot thermal tp is reached as if the critical is reached. > > If pm-utils does: > echo 1 >/sys/class/thermal/S4_capable > it has to make sure it picks up acpi thermal hot event and initiates > S4. If S4 fails for whatever reasons (no swap, > stroking some kernel drivers fails, unmounting file systems fails, ...), > it has to make sure to force a system shutdown (just call /sbin/poweroff > the same way the kernel does currently with a critical thermal event?). > Emergency shutdown is then out of kernels hand (as it is currently for HOT > anyway which is dangerous). > > Hmm, this is acpi specific, possibly it should be a new dir here: > /sys/firmware/acpi/thermal/S4_capable > or something else? > Your idea looks good to me, but, the DeviceKit-power will rename to upower, and Kay is the udev expert. I think will need kay's professional comment on udev side. Hi Kay, We are discussing about how to handle the situtation if BIOS ACPI didn't return the _CRT value, and even have _HOT value, if S4 fail, what can we do on kernel space and userland. _CRT value is the shutdown critical temperature _HOT value is the critical temperature for sleep (entry to S4) Per ACPI spec: The platform vendor should define _HOT to be far enough below _CRT so as to allow OSPM enough time to transition the system into the S4 sleeping state. Currently, there have a bit platform provider (OEM/ODM) only return the _HOT, but didn't have _CRT value. But, if _HOT S4 fail, the system components might dangerous if there have no any hardware protected Mechanism. Thomas's idea is add a sysfs interface /sys/class/thermal/S4_capable for userland to tell kernel userland component (pm-util or upower?) already take the _HOT event and try to do S4. How do you think about this idea? Thank's Joey Lee -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
