Re: [PATCH 7/7] powerpc/eeh: Add eeh_force_recover to debugfs

Oliver [off-list ref] writes:

On Fri, Feb 8, 2019 at 11:32 PM Michael Ellerman [off-list ref] wrote:

quoted

Oliver O'Halloran [off-list ref] writes:

quoted

This patch adds a debugfs interface to force scheduling a recovery event.
This can be used to recover a specific PE or schedule a "special" recovery
even that checks for errors at the PHB level.
To force a recovery of a normal PE, use:

 echo '<#pe>:<#phb>' > /sys/kernel/debug/powerpc/eeh_force_recover

To force a scan broken PHBs:

 echo 'null' > /sys/kernel/debug/powerpc/eeh_force_recover

Why 'null', that seems like an odd choice. Why not "all" or "scan" or
something?

When an EEH event occurs the bit that is sent to the event handler is
just a pointer the the struct eeh_pe. If the pointer is null it's then
treated as a special event which indicates a PHB failure. I agree it's
a bit dumb, but I don't really expect anyone except me or samb to use
this interface so I went with what would make sense to someone
familiar with the internals.

Yeah, nah. Let's use something that's at least vaguely self documenting
so people like me can have some clue what it's doing.

cheers