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Message-ID: <CAK3cCByGeAK2H83bP0wy=kC_+kj4Q8cFHPQ1gYUJ=uv4gs-T-A@mail.gmail.com>
Date: Mon, 23 Sep 2013 22:43:55 +0800
From: cinifr <cinifr@...il.com>
To: Ian Campbell <ijc@...lion.org.uk>
Cc: "linux-sunxi@...glegroups.com" <linux-sunxi@...glegroups.com>,
"coosty@....com" <coosty@....com>,
"maxime.ripard@...e-electrons.com" <maxime.ripard@...e-electrons.com>,
"daniel.lezcano@...aro.org" <daniel.lezcano@...aro.org>,
"linux@....linux.org.uk" <linux@....linux.org.uk>,
"tglx@...utronix.de" <tglx@...utronix.de>,
"linux-arm-kernel@...ts.infradead.org"
<linux-arm-kernel@...ts.infradead.org>,
"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
"mark.rutland@....com" <mark.rutland@....com>,
"pawel.moll@....co" <pawel.moll@....co>,
"rob.herring@...xeda.com" <rob.herring@...xeda.com>
Subject: Re: [PATCH 1/3] Add smp support for Allwinner A20(sunxi 7i).
> In which case this kernel patch needs instead to speak the bootloader
> wakeup protocol instead of speaking to the h/w directly like you've done
> here, right?
>
> Or is it possible for the bootloader to set these things up and then put
> the CPU back to sleep such that it both retains any settings and is
> wakable by this patch? This code contains core resets and power control,
> which makes me suspect not.
And I think secondary cpus remains setting after h/w boot.
>> > Wouldn't it be better to do all this stuff in the bootloader and
>> either
>> > implement PSCI or have the bootloader do the traditional holding pen
>> and
>> > mbox address thing?
Uboot doesnot support PSCI, it use traditional holding pen for sunxi
platform now.
>> >
>> I have modified uboot to set cntfrq and cntvoff in all smp cpus,and it
>> works well. I guess kernel should believe all cpu should be all same
>> when kernel boot. Bootloader should do it to ensure that.
>
> Yes, I think all CPUs must be in the same state at boot.
>
> But if you've done all that then what is this patch for?
>
> Do you have links to your u-boot patches?
>
> Ian.
Yes, This is my patch for uboot.
My working uboot code is in https://github.com/linux-sunxi/u-boot-sunxi.git
Note this is only test patch. I have not commit it formally for uboot.
Fan
Download attachment "0001-Add-setting-CNTVOFF-and-CNTFRQ-for-all-smp-cpus.patch" of type "application/octet-stream" (11285 bytes)
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