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From: kapilh@broadcom.com (Kapil Hali)
To: linux-arm-kernel@lists.infradead.org
Subject: [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

      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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