Thanks for your comments, Ville! On Fri, 2023-11-17 at 09:19 +0200, Ville Syrjälä wrote: > On Thu, Nov 16, 2023 at 01:27:00PM +0200, Luca Coelho wrote: > > Since we're abstracting the display code from the underlying driver > > (i.e. i915 vs xe), we can't use the uncore's spinlock to protect > > critical sections of our code. > > > > After further inspection, it seems that the spinlock is not needed at > > all and this can be handled by disabling preemption and interrupts > > instead. > > uncore.lock has multiple purposes: > 1. serialize all register accesses to the same cacheline as on > certain platforms that can hang the machine Okay, do you remember which platforms? I couldn't find any reference to this reason. Also, the only place where where we take the uncore.lock is in this vblank code I changed, where the only explanation I found was about timing, specifically when using RT-kernels and in very old and slow platforms... (this was added 10 years ago). > 2. protect the forcewake/etc. state > > 1 is relevant here, 2 is not. Okay, good that we have only one known problem. :) -- Cheers, Luca.
