On Wed, 2017-07-19 at 06:59:10 UTC, Nicholas Piggin wrote: > Unrecovered MCE and HMI errors are sent through a special restart OPAL > call to log the platform error. The downside is that they don't go > through normal Linux crash paths, so they don't give much information > to the Linux console. > > Change this by providing a special crash function which does some of > the console flushing from the panic() path before calling firmware to > reboot. > > The downside of this is a little more code to execute before reaching > the firmware reboot. However in practice, it's critical to get the > Linux console messages output in order to debug a problem. So this is > a desirable tradeoff. > > Note on the implementation: It is difficult to plumb a custom reboot > handler into the panic path, because panic does a little bit too much > work. For example, it will try to delay with the timebase, but that > may be corrupted in some cases resulting in a hang without reaching > the platform reboot. Another problem is that panic can invoke the > crash dump code which is not what we want in the case of a hardware > platform error. Long-term the best solution will be to rework the > panic path so it can be suitable for this kind of panic, but for now > we just duplicate a bit of the code. > > Signed-off-by: Nicholas Piggin <npig...@gmail.com> > Reviewed-by: Mahesh Salgaonkar <mah...@linux.vnet.ibm.com>
Series applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/b746e3e01e70d23ef53dcde1203ab7 cheers
