From mboxrd@z Thu Jan 1 00:00:00 1970 From: khilman@kernel.org (Kevin Hilman) Date: Wed, 17 Sep 2014 17:39:29 -0700 Subject: exynos5420/arndale-octa: imprecise external aborts on exynos_defconfig In-Reply-To: (Thomas Abraham's message of "Sat, 13 Sep 2014 18:29:58 +0530") References: <7h7g1bwbyh.fsf@deeprootsystems.com> Message-ID: <7hk351ep8e.fsf@deeprootsystems.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Thomas Abraham writes: > On Thu, Sep 11, 2014 at 12:16 AM, Kevin Hilman wrote: >> Tyler Baker writes: >> >>> Exynos5420-based Arndale octa boards have recently started failing boot >>> tests due to imprecise external aborts. This only appears to happen >>> when using exynos_defconfig and boots fine with multi_v7_defconfig. The >>> issue seems to be intermittent, so is not reliably reproducable and >>> difficult to bisect. Here are a few boot logs from recent >>> mainline/linux-next kernels that are failing: >> >> FYI, I'm seeing the same periodic aborts. For example, here's my boot >> of next-20140910: >> http://images.armcloud.us/kernel-ci/next/next-20140910/arm-exynos_defconfig/boot-exynos5420-arndale-octa.html >> >> However, my userspace is much simpler and doesn't seem to cause a panic, >> so my boot tests report passing. (I should fixup my scripts so these >> imprecise aborts are reported as a FAIL.) >> >> I'm glad you pointed out that it happens only with exynos_defconfig and >> not multi_v7_defconfig because I noticed that too. I haven't had the >> time to track it any further than that, so maybe the exynos folks can >> help track it down from here. >> >> Thanks for reporting this, >> >> Kevin > > Hi Tyler, Kevin, > > From the bootlog you have shared, > > [ 1.060016] CPU4: failed to come online > [ 2.070031] CPU5: failed to come online > [ 3.080049] CPU6: failed to come online > [ 4.090066] CPU7: failed to come online > [ 4.090099] Brought up 4 CPUs > [ 4.090109] SMP: Total of 4 processors activated. > [ 4.090119] CPU: WARNING: CPU(s) started in wrong/inconsistent > modes (primary CPU mode 0x13) > [ 4.090128] CPU: This may indicate a broken bootloader or firmware. > > Would it be possible to set max cpus to 1, disable switcher and try > again. I don't have a arndale octa board but I have tested mainline > kernel with smdk5420 board. It boots all eight CPUs, switcher works > fine and there are no imprecise aborts seen. Sorry for the delay, I'm travelling this week. FWIW, the same CPU boot failures you hilight above are happening on multi_v7_defconfig[1] which is not getting the imprecise abort. This is only happening on exynos_defconfig[2], so I'm curious why you think the switcher or NR_CPUS might be the issues. Anyways, I narrowed this down a bit and discovered it's CONFIG_EXYNOS5420_MCPM=y that's the root cause. If I use exynos_defconfig and then disable that option, I don't get any more imprecise aborts. Kevin [1] http://images.armcloud.us/kernel-ci/mainline/v3.17-rc5-25-g8ba4caf/arm-multi_v7_defconfig/boot-exynos5420-arndale-octa.html [2] http://images.armcloud.us/kernel-ci/mainline/v3.17-rc5-25-g8ba4caf/arm-exynos_defconfig/boot-exynos5420-arndale-octa.html