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From: huangtao@rock-chips.com (Huang Tao)
To: linux-arm-kernel@lists.infradead.org
Subject: [RESEND PATCH] ARM: dts: make arch-timer always on in rk3288 soc
Date: Fri, 29 Aug 2014 11:06:40 +0800	[thread overview]
Message-ID: <53FFEE40.3010001@rock-chips.com> (raw)
In-Reply-To: <20140828151121.GM14650@leverpostej>

Hi, Mark:

? 2014?08?28? 23:11, Mark Rutland ??:
> To clarify: if there are low power states that the CPU can enter where
> we lose state, then this patch isn't correct.
Right now, the software of RK3288 SoC only support CPU hotplug
(cpu_on/off) and power off all CPUs on suspend.
We do not implement cpuidle to power off CPU. Do you think we should
introduce a broadcast timer?
On our early kernel, I never see any interrupt on a broadcast timer
(yes, we implement it with a external timer).
>
> A more general approach would be to enable the broadcast hrtimer for
> arm, as has been done for arm64.
Yes. I think it should be done by arm framework.
>
> See commit 5d1638acb9f6 (tick: Introduce hrtimer based broadcast) which
> introduced the broadcast hrtimer, and commit 9358d755bd5c (arm64:
> kernel: initialize broadcast hrtimer based clock event device) which
> added the requisite plumbing for arm64.

WARNING: multiple messages have this Message-ID (diff)
From: Huang Tao <huangtao-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
To: Mark Rutland <mark.rutland-5wv7dgnIgG8@public.gmane.org>
Cc: Kever Yang <kever.yang-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org"
	<heiko-4mtYJXux2i+zQB+pC5nmwQ@public.gmane.org>,
	"dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org"
	<dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	"sonnyrao-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org"
	<sonnyrao-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>,
	"addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<addy.ke-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<cf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<xjq-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"lyz-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<lyz-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	"hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org"
	<hj-TNX95d0MmH7DzftRWevZcw@public.gmane.org>,
	Rob Herring <robh+dt-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>,
	Pawel Moll <Pawel.Moll-5wv7dgnIgG8@public.gmane.org>,
	Ian Campbell
	<ijc+devicetree-KcIKpvwj1kUDXYZnReoRVg@public.gmane.org>,
	Kumar Gala <galak-sgV2jX0FEOL9JmXXK+q4OQ@public.gmane.org>,
	Russell King <linux-lFZ/pmaqli7XmaaqVzeoHQ@public.gmane.org>,
	"devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	"linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org"
	<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>,
	"linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org"
	<linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
	lorenzo.pieralisi-5wv7dgnIgG8@public.gmane.org
Subject: Re: [RESEND PATCH] ARM: dts: make arch-timer always on in rk3288 soc
Date: Fri, 29 Aug 2014 11:06:40 +0800	[thread overview]
Message-ID: <53FFEE40.3010001@rock-chips.com> (raw)
In-Reply-To: <20140828151121.GM14650@leverpostej>

Hi, Mark:

在 2014年08月28日 23:11, Mark Rutland 写道:
> To clarify: if there are low power states that the CPU can enter where
> we lose state, then this patch isn't correct.
Right now, the software of RK3288 SoC only support CPU hotplug
(cpu_on/off) and power off all CPUs on suspend.
We do not implement cpuidle to power off CPU. Do you think we should
introduce a broadcast timer?
On our early kernel, I never see any interrupt on a broadcast timer
(yes, we implement it with a external timer).
>
> A more general approach would be to enable the broadcast hrtimer for
> arm, as has been done for arm64.
Yes. I think it should be done by arm framework.
>
> See commit 5d1638acb9f6 (tick: Introduce hrtimer based broadcast) which
> introduced the broadcast hrtimer, and commit 9358d755bd5c (arm64:
> kernel: initialize broadcast hrtimer based clock event device) which
> added the requisite plumbing for arm64.



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WARNING: multiple messages have this Message-ID (diff)
From: Huang Tao <huangtao@rock-chips.com>
To: Mark Rutland <mark.rutland@arm.com>
Cc: Kever Yang <kever.yang@rock-chips.com>,
	"heiko@sntech.de" <heiko@sntech.de>,
	"dianders@chromium.org" <dianders@chromium.org>,
	"sonnyrao@chromium.org" <sonnyrao@chromium.org>,
	"addy.ke@rock-chips.com" <addy.ke@rock-chips.com>,
	"cf@rock-chips.com" <cf@rock-chips.com>,
	"xjq@rock-chips.com" <xjq@rock-chips.com>,
	"wulf@rock-chips.com" <wulf@rock-chips.com>,
	"lyz@rock-chips.com" <lyz@rock-chips.com>,
	"hj@rock-chips.com" <hj@rock-chips.com>,
	Rob Herring <robh+dt@kernel.org>, Pawel Moll <Pawel.Moll@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	Kumar Gala <galak@codeaurora.org>,
	Russell King <linux@arm.linux.org.uk>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	lorenzo.pieralisi@arm.com
Subject: Re: [RESEND PATCH] ARM: dts: make arch-timer always on in rk3288 soc
Date: Fri, 29 Aug 2014 11:06:40 +0800	[thread overview]
Message-ID: <53FFEE40.3010001@rock-chips.com> (raw)
In-Reply-To: <20140828151121.GM14650@leverpostej>

Hi, Mark:

在 2014年08月28日 23:11, Mark Rutland 写道:
> To clarify: if there are low power states that the CPU can enter where
> we lose state, then this patch isn't correct.
Right now, the software of RK3288 SoC only support CPU hotplug
(cpu_on/off) and power off all CPUs on suspend.
We do not implement cpuidle to power off CPU. Do you think we should
introduce a broadcast timer?
On our early kernel, I never see any interrupt on a broadcast timer
(yes, we implement it with a external timer).
>
> A more general approach would be to enable the broadcast hrtimer for
> arm, as has been done for arm64.
Yes. I think it should be done by arm framework.
>
> See commit 5d1638acb9f6 (tick: Introduce hrtimer based broadcast) which
> introduced the broadcast hrtimer, and commit 9358d755bd5c (arm64:
> kernel: initialize broadcast hrtimer based clock event device) which
> added the requisite plumbing for arm64.




  parent reply	other threads:[~2014-08-29  3:06 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-08-28  1:40 [RESEND PATCH] ARM: dts: make arch-timer always on in rk3288 soc Kever Yang
2014-08-28  1:40 ` Kever Yang
2014-08-28  1:40 ` Kever Yang
2014-08-28  9:17 ` Mark Rutland
2014-08-28  9:17   ` Mark Rutland
2014-08-28  9:17   ` Mark Rutland
2014-08-28 15:11   ` Mark Rutland
2014-08-28 15:11     ` Mark Rutland
2014-08-28 15:11     ` Mark Rutland
2014-08-29  0:35     ` Kever Yang
2014-08-29  0:35       ` Kever Yang
2014-08-29  0:35       ` Kever Yang
2014-08-29  3:06     ` Huang Tao [this message]
2014-08-29  3:06       ` Huang Tao
2014-08-29  3:06       ` Huang Tao
2014-08-29 11:22       ` Mark Rutland
2014-08-29 11:22         ` Mark Rutland
2014-08-29 11:22         ` Mark Rutland
2014-08-29 11:44         ` Huang Tao
2014-08-29 11:44           ` Huang Tao
2014-08-29 11:44           ` Huang Tao

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