Re: [PATCH v2] ARM: dts: sunxi: Add regulators for LeMaker BananaPi

From: "Timo Sigurdsson" <public_timo.s@silentcreek.de>
To: maxime.ripard@free-electrons.com
Cc: khilman@kernel.org, robh+dt@kernel.org, pawel.moll@arm.com,
	mark.rutland@arm.com, ijc+devicetree@hellion.org.uk,
	galak@codeaurora.org, linux@arm.linux.org.uk,
	devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org, linux-sunxi@googlegroups.com,
	wens@csie.org, tyler.baker@linaro.org, olof@lixom.net
Subject: Re: [PATCH v2] ARM: dts: sunxi: Add regulators for LeMaker BananaPi
Date: Wed,  7 Oct 2015 19:58:40 +0200 (CEST)	[thread overview]
Message-ID: <20151007175840.A70656C800D4@dd34104.kasserver.com> (raw)
In-Reply-To: <20151007174904.GH2278@lukather>

Hi Maxime,

Maxime Ripard schrieb am 07.10.2015 19:49:

> Hi Timo,
> 
> On Wed, Oct 07, 2015 at 05:49:18PM +0200, Timo Sigurdsson wrote:
>> Hi Kevin,
>> Hi Maxime,
>> 
>> Kevin Hilman schrieb am 07.10.2015 16:36:
>> 
>> > "Timo Sigurdsson" <public_timo.s@silentcreek.de> writes:
>> >> I still think that the lower voltages may be the cause of your problem
>> >> with that specific board, so could you please test the attached patch on
>> >> top of my patch that you first experienced the problem with? Please let 
>> >> us know whether this solves your issue or whether we need to dig deeper.
>> > 
>> > Thanks for the patch.  Looks like it's the OPPs.
>> > 
>> > I went back to next-20150923 and verified it still fails.  Then, I
>> > applied your patch and saw that it boots just fine.
>> 
>> Good. Then we can easily fix this, I guess.
>> 
>> @Maxime: How should we handle this? In its current form, the patch applies
>> only to the BananaPi dts by overriding the inherited opp from the SoC dtsi.
>> In an earlier discussion, it was said that this can be done, even though it
>> might not be the most elegant approach. But then again, I think it
>> shouldn't be necessary to change the opp in the sun7i-a20.dtsi for all A20
>> boards since this is - to my knowledge - the first and only report that an
>> A20 board has stability issues at the lower voltages (although not too many
>> boards use voltage scaling yet).
> 
> If you count only the number of boards, indeed, but if you count the
> number of devices actually used in the field, we cover already a
> significant portion of them.
> 
>> So, would you prefer to keep this as a patch for BananaPi only, or
>> change the dtsi for all A20 devices instead?
> 
> Yeah, we probably can keep that for bananapi only at the moment, and
> try to generalize that afterwards.

Ok.

> 
>> In case we keep it as it is, what is the correct commit to point to as
>> "Fixes commit ..."? I'd say it fixes the initial opp commit for A20, since
>> that's where these voltages were defined. But then again, if we don't
>> change the dtsi, should I point to my regulator patch instead?
> 
> I don't think it fixes anything at this point. We droped your commit
> that was using the A20 OPPs, so in the history so far we don't have
> anything to fix, just enable cpufreq again.

Ok. I'll send a third version of the regulator patch then with the
updated opp included.

Thanks,

Timo