From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Timo Sigurdsson" Subject: Re: [PATCH v2] ARM: dts: sunxi: Add regulators for LeMaker BananaPi Date: Fri, 25 Sep 2015 17:05:58 +0200 (CEST) Message-ID: <20150925150558.184E66C8385C@dd34104.kasserver.com> References: <1438532305-5884-1-git-send-email-public_timo.s@silentcreek.de> <20150818153631.GH2547@lukather> Reply-To: public_timo.s-fWgRPtSzPNU3WX+qO2AYSQ@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , To: maxime.ripard-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, khilman-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org Cc: robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org, pawel.moll-5wv7dgnIgG8@public.gmane.org, mark.rutland-5wv7dgnIgG8@public.gmane.org, ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org, galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org, linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org, devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-sunxi-/JYPxA39Uh5TLH3MbocFFw@public.gmane.org, wens-jdAy2FN1RRM@public.gmane.org, tyler.baker-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, olof-nZhT3qVonbNeoWH0uzbU5w@public.gmane.org List-Id: devicetree@vger.kernel.org Hi Kevin, Kevin Hilman schrieb am 25. Sept 2015 01:57: > On Tue, Aug 18, 2015 at 8:36 AM, Maxime Ripard > wrote: >> On Sun, Aug 02, 2015 at 06:18:25PM +0200, Timo Sigurdsson wrote: >>> sun7i-a20-bananapi.dts doesn't contain regulator nodes for the AXP209 >>> PMU >>> driver, so add them to allow for voltage-scaling with cpufreq-dt. >>> >>> Signed-off-by: Timo Sigurdsson >> >> Queued, thanks! >> Maxime >=20 > kernelci.org started finding boot faiulres[1] on bananapi linux-next > around next-20150918, but it was only failing in some labs and not > others. I finally bisected it down to this patch, which landed in > linux-next in the form of 2d665a8a8350 ARM: dts: sunxi: Add regulators > for LeMaker BananaPi. Reverting that commit on top of next-20150923 > gets my bananapi booting again. >=20 > Note it's kind of an interesting boot failure. The kernel boots fully > to a shell, but panics after running a few commands. In particular > 'dmesg -n1' seems to trigger it usually[2]. >=20 > Kevin >=20 > [1] > http://kernelci.org/boot/sun7i-a20-bananapi/job/next/kernel/next-20150923= /defconfig/multi_v7_defconfig/lab/lab-khilman/?_id=3D5602504359b514be146c32= 6f > [2] > http://storage.kernelci.org/next/next-20150923/arm-multi_v7_defconfig/lab= -khilman/boot-sun7i-a20-bananapi.html >=20 Thanks for your feedback. I'm traveling at the moment, so I can't do any te= sting but just guess wildly. I know, though, that I used dmesg frequently w= hen I did my own testing before submitting the patch and could not see such= behavior. Before this commit, the CPU of your BananaPi runs at 1.4 volts constantly. = With this commit applied, the CPU voltage should vary between 1.0-1.4 volts= depending on the frequency and defined operating points. Hence, one of my = guesses would be that your CPU is not stable at the lower voltages. Could y= ou modify the voltages for the defined frequencies in sun7i-a20.dtsi and te= st if that solves your issue? Say, raise the voltage by 0.1 volts for each = operating point (but no higher than 1.4). I actually had a different patch = that applied slightly higher voltages taken from the original fex for by Le= Maker, but the feedback was, unless there are actual reports about boards n= ot running stable at the current settings, we just keep them instead. So, I= 'm curious if you happen to have a board that requires slightly higher volt= ages to run stable. Regards,=20 Timo --=20 You received this message because you are subscribed to the Google Groups "= linux-sunxi" group. To unsubscribe from this group and stop receiving emails from it, send an e= mail to linux-sunxi+unsubscribe-/JYPxA39Uh5TLH3MbocFF+G/Ez6ZCGd0@public.gmane.org For more options, visit https://groups.google.com/d/optout.