Hi Kevin, On Wed, Aug 27, 2014 at 3:55 AM, Kevin Hilman <khilman@xxxxxxxxxx> wrote: > On Tue, Aug 26, 2014 at 8:15 AM, Kevin Hilman <khilman@xxxxxxxxxx> wrote: >> On Mon, Aug 25, 2014 at 10:25 PM, Chander Kashyap <k.chander@xxxxxxxxxxx> wrote: > > [...] > >>>> >>>> Can you clarify how you're setting the voltages to ensure stability? >>> >>> below is the diff : wip/exynos/integ >> >> Thanks. >> >> I've applied your patch, and bootup shows vdd_arm and vdd_kfc at >> 1500mV, but still when booting with cpuidle enabled (bL switcher >> disabled), I'm seeing lockups with no kernel output. With CPUidle >> disabled, things are pretty stable. >> >> What tree are you using to test this out on 5420? I'm using mainline >> v3.17-rc1 + DT patch for CPUidle and this cpufreq series. See my >> wip/exynos/integ branch at >> git://git.kernel.org/pub/scm/linux/kernel/git/khilman/linux.git. > > I mis-stated this. Actually my tree is based on the v3.17-rc1 branch > of the exynos-reference tree[1] + the above mentioned patches for > cpuidle and cpufreq. > > Also, I've narrowed down the instability a bit, and it's not related > to CPUidle. I can now trigger a boot hang even without CPUidle > enabled. Here's a quick way to cause a boot lockup. With the switcher > disabled, I enable CPUfreq and set the default governor to > performance. As soon as cpufreq driver loads, it tries to use the top > frequences for both clusters, and it hangs. > > Selectively disabling frequencies, I narrowed it down to the 1.3GHz > and 1.2GHz frequencies of the little cluster. With these commented > out in the DT, it will fully boot with the performance governor > enabled. > > So that leads to the question. Are all of the operating points in > exynos5420.dtsi valid for exynos5800, and have they been validated? I tried to recreate the boot lockup issue using the same steps you listed above for the Exynos5800 peach-pi platform (Chromebook2), but I do not see any issues. I can see both clusters with max clock speed after boot (1.8GHz and 1.3GHz). I am using v3.17-rc2 + CPUFreq Patches + max77802 regulator support patches for Chromebook2 + temp hack to set A15 voltage to 1.35V and A7 voltage to 1.3V. Sorry for the delaying in following up. Thanks, Thomas. > > Kevin > > [1]https://github.com/exynos-reference/kernel.git > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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