From mboxrd@z Thu Jan 1 00:00:00 1970 From: Geert Uytterhoeven Date: Fri, 07 Nov 2014 07:59:25 +0000 Subject: Re: (bisected) Lock up on sh73a0/kzm9g on cpuidle initialization Message-Id: List-Id: References: <545BE1DE.6060900@linaro.org> In-Reply-To: <545BE1DE.6060900@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-arm-kernel@lists.infradead.org Hi Daniel, On Thu, Nov 6, 2014 at 10:02 PM, Daniel Lezcano wrote: > On 11/06/2014 09:38 PM, Geert Uytterhoeven wrote: >> When CONFIG_CPU_IDLE=y, the kernel locks up during cpuidle initialization >> on Renesas sh73a0/kzm9g-reference, which has a dual-core Cortex-A9. >> >> Last message is: >> >> DMA: preallocated 256 KiB pool for atomic coherent allocations >> >> After this it's supposed to print: >> >> cpuidle: using governor ladder >> cpuidle: using governor menu >> >> I've bisected this to commit 442bf3aaf55a91ebfec71da46a4ee10a3c905bcc >> ("sched: Let the scheduler see CPU idle states"). >> >> Reverting that commit, and commit 83a0a96a5f26d974580fd7251043ff70c8f1823d >> ("sched/fair: Leverage the idle state info when choosing the "idlest" >> cpu") which >> depends on it, fixes the problem. >> >> I saw the discussion "lockdep splat in CPU hotplug", so I enabled lockdep >> debugging, but didn't see a lockdep splat. > > Did you try the fix attached ? > > https://lkml.org/lkml/2014/10/22/722 Thanks, I didn't try that. However, this patch seems to be in v3.18-rc3, so I'm already using it. Hence it doesn't fix the problem for me. On another board, with a dual Cortex-A15, the problem doesn't show up. Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds