From mboxrd@z Thu Jan 1 00:00:00 1970 From: daniel.lezcano@linaro.org (Daniel Lezcano) Date: Thu, 06 Nov 2014 22:02:22 +0100 Subject: (bisected) Lock up on sh73a0/kzm9g on cpuidle initialization In-Reply-To: References: Message-ID: <545BE1DE.6060900@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org 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 > I'm using CONFIG_TREE_RCU=y, as this is SMP without PREEMPT. > > Anyone with a clue? > > 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 > -- Linaro.org ? Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog