From: Kapil Hali <kapilh@broadcom.com>
To: Russell King - ARM Linux <linux@arm.linux.org.uk>
Cc: Rob Herring <robh+dt@kernel.org>, Pawel Moll <pawel.moll@arm.com>,
"Mark Rutland" <mark.rutland@arm.com>,
Ian Campbell <ijc+devicetree@hellion.org.uk>,
Kumar Gala <galak@codeaurora.org>, Ray Jui <rjui@broadcom.com>,
Scott Branden <sbranden@broadcom.com>,
Jon Mason <jonmason@broadcom.com>,
Florian Fainelli <f.fainelli@gmail.com>,
"Gregory Fong" <gregory.0xf0@gmail.com>,
Lee Jones <lee@kernel.org>, Hauke Mehrtens <hauke@hauke-m.de>,
Heiko Stuebner <heiko@sntech.de>,
Kever Yang <kever.yang@rock-chips.com>,
Maxime Ripard <maxime.ripard@free-electrons.com>,
Olof Johansson <olof@lixom.net>, "Paul Walmsley" <paul@pwsan.com>,
Linus Walleij <linus.walleij@linaro.org>,
Chen-Yu Tsai <wens@csie.org>, <devicetree@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>,
<bcm-kernel-feedback-list@broadcom.com>
Subject: Re: [PATCH RESEND 0/4] SMP support for Broadcom NSP
Date: Fri, 6 Nov 2015 17:39:43 +0530 [thread overview]
Message-ID: <563C9887.5090406@broadcom.com> (raw)
In-Reply-To: <20151105093443.GO8644@n2100.arm.linux.org.uk>
On 11/5/2015 3:04 PM, Russell King - ARM Linux wrote:
> On Thu, Nov 05, 2015 at 12:51:17AM -0500, Kapil Hali wrote:
>> Hi,
>>
>> This series adds SMP support for Broadcom's Northstar Plus SoC.
>>
>> There are similar SMP enablement methods for many ARMv7 bsed SoCs.
>> BCM NSP SoC, has a typical such mechanism - after power-on, the
>> secondary core is held in a standby state, primary core provides a
>> startup address for the secondary core and wakes it up. Booting of
>> the secondary core is serialized using pen_release global variable.
>
> Why do you need the pen_release stuff? The above implies that you
> have only one secondary core, and you can control when it comes out
> of standby state.
>
We can initiate a wake-up of the secondary core. I tested the changes
without pen_release method and it works. However, as I understand, I
think there is no other way for the primary core to know if the
secondary core has come out of standby state other than pen_release
mechanism. When there is no other method available, will not
smp_boot_secondary() always return successful wake-up of the
secondary core?
> Please, don't assume that the pen_release stuff is any kind of recommended
> or standardised system. It isn't. It's a hack for ARMs evaluation
> platforms.
>
Got it. As pen_release is forbidden, I will change the SMP mechanism
to remove pen_release method in the new patch set.
Thanks,
Kapil
prev parent reply other threads:[~2015-11-06 12:09 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-05 5:51 [PATCH RESEND 0/4] SMP support for Broadcom NSP Kapil Hali
2015-11-05 5:51 ` [PATCH RESEND 1/4] dt-bindings: add SMP enable-method " Kapil Hali
2015-11-05 20:48 ` Rob Herring
2015-11-05 20:57 ` Scott Branden
2015-11-05 5:51 ` [PATCH RESEND 2/4] ARM: dts: add SMP support " Kapil Hali
2015-11-05 5:51 ` [PATCH RESEND 3/4] ARM: BCM: Add " Kapil Hali
2015-11-05 9:44 ` Linus Walleij
2015-11-06 12:15 ` Kapil Hali
2015-11-16 23:35 ` kbuild test robot
2015-11-05 5:51 ` [PATCH RESEND 4/4] ARM: BCM: Add SMP support for Broadcom 4708 Kapil Hali
2015-11-05 9:34 ` [PATCH RESEND 0/4] SMP support for Broadcom NSP Russell King - ARM Linux
2015-11-05 20:25 ` Hauke Mehrtens
2015-11-06 12:25 ` Kapil Hali
2015-11-06 12:09 ` Kapil Hali [this message]
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