Messages in this thread | | | Date | Wed, 14 Feb 2018 10:38:35 +0100 | From | Peter Zijlstra <> | Subject | Re: [PATCH] watchdog: hpwdt: Remove spinlock acquire and BIOS calls from NMI context |
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On Wed, Feb 14, 2018 at 10:31:59AM +0100, Ingo Molnar wrote: > Because in this particular case it does not appear to be so: the reason for the > BIOS/firmware call appears to be to determine how we nmi_panic() after receiving > an NMI that no other NMI handler handled: with a passive-aggressive "I don't know" > panic message or with a slightly more informative panic message.
However much I like just ripping all that out, I think the ROM call actually does that logging, or that is how I read things.
If you look at the original Changelog for that driver:
Hp is providing a Hardware WatchDog Timer driver that will only work with the specific HW Timer located in the HP ProLiant iLO 2 ASIC. The iLO 2 HW Timer will generate a Non-maskable Interrupt (NMI) 9 seconds before physically resetting the server, by removing power, so that the event can be logged to the HP Integrated Management Log (IML), a Non-Volatile Random Access Memory (NVRAM). The logging of the event is performed using the HP ProLiant ROM via an Industry Standard access known as a BIOS Service Directory Entry.
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