Re: [FSL P50xx] IRQ issues
From: Nicholas Piggin <npiggin@gmail.com>
Date: 2021-07-06 04:26:47
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:quoted
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=019b3fd94ba73d3ac615f0537440b81f129821f6This 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
quoted hunk ↗ jump to hunk
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