Excerpts from Nicholas Piggin's message of July 6, 2021 9:36 am: > Excerpts from Christian Zigotzky's message of July 6, 2021 4:49 am: >> Hi All, >> >> Our FSL P50xx machines don't boot anymore because of IRQ issues. [1] >> >> Please check the IRQ changes in the latest PowerPC updates 5.14-1. [2] >> >> Thanks, >> Christian >> >> [1] >> https://forum.hyperion-entertainment.com/download/file.php?id=2592&mode=view >> [2] >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=019b3fd94ba73d3ac615f0537440b81f129821f6 > > This looks like mtmsrd in the 64e code. I think this should fix it. > > QEMU does not seem to trap on this, maybe something to improve.
With a patch to qemu to make it take an illegal instruction on mtmsrd I can reproduce basically what you have, and this patch makes it work. I think this is the best short term fix. Thanks, Nick > > Thanks, > Nick > -- > > diff --git a/arch/powerpc/kernel/interrupt_64.S > b/arch/powerpc/kernel/interrupt_64.S > index 4063e8a3f704..d4212d2ff0b5 100644 > --- a/arch/powerpc/kernel/interrupt_64.S > +++ b/arch/powerpc/kernel/interrupt_64.S > @@ -311,9 +311,13 @@ END_BTB_FLUSH_SECTION > * trace_hardirqs_off(). > */ > li r11,IRQS_ALL_DISABLED > - li r12,-1 /* Set MSR_EE and MSR_RI */ > stb r11,PACAIRQSOFTMASK(r13) > +#ifdef CONFIG_PPC_BOOK3S > + li r12,-1 /* Set MSR_EE and MSR_RI */ > mtmsrd r12,1 > +#else > + wrteei 1 > +#endif > > /* Calling convention has r9 = orig r0, r10 = regs */ > mr r9,r0 >
