From: bilhuang@nvidia.com (Bill Huang)
To: linux-arm-kernel@lists.infradead.org
Subject: [RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare
Date: Thu, 14 Mar 2013 02:28:07 -0700 [thread overview]
Message-ID: <1363253287.3311.32.camel@bilhuang-vm1> (raw)
In-Reply-To: <20130314092132.GE18519@tbergstrom-lnx.Nvidia.com>
On Thu, 2013-03-14 at 17:21 +0800, Peter De Schrijver wrote:
> On Thu, Mar 14, 2013 at 03:15:11AM +0100, Bill Huang wrote:
>
> > I don't think deferring will work either, considering the usage of DVFS,
> > device voltage is tightly coupled with frequency, when clock rate is
> > about to increase, we have to boost voltage first and we can lower the
> > voltage after the clock rate has decreased. All the above sequence have
> > to be guaranteed or you might crash, so deferring not only make thing
> > complicated in controlling the order but also hurt performance.
>
> But we could use notifiers in clk_prepare/clk_unprepare to set the voltage no?
> As clk_prepare/clk_unprepare have to be called before clk_enable or after
> clk_disable, the voltage can be raised to a safe level, before the clock
> becomes active.
Thanks Peter, actually I'm just about to propose my v2 RFC which add
notifier in clk_prepare/clk_unprepare.
>
> Cheers,
>
> Peter.
next prev parent reply other threads:[~2013-03-14 9:28 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-03-12 12:37 [RFC 1/1] clk: Add notifier support in clk_prepare_enable/clk_disable_unprepare Bill Huang
2013-03-12 13:40 ` Russell King - ARM Linux
2013-03-13 1:47 ` Bill Huang
2013-03-13 4:42 ` Stephen Warren
2013-03-13 5:08 ` Bill Huang
2013-03-13 5:24 ` Stephen Warren
2013-03-13 5:40 ` Bill Huang
2013-03-13 18:10 ` Stephen Warren
2013-03-14 2:15 ` Bill Huang
2013-03-14 9:21 ` Peter De Schrijver
2013-03-14 9:28 ` Bill Huang [this message]
2013-03-14 17:54 ` Stephen Warren
2013-03-15 1:20 ` Bill Huang
2013-03-15 5:22 ` Stephen Warren
2013-03-15 5:48 ` Bill Huang
2013-03-15 9:39 ` Peter De Schrijver
2013-03-15 10:08 ` Ulf Hansson
2013-03-15 12:06 ` Bill Huang
2013-03-15 12:33 ` Ulf Hansson
2013-03-15 19:38 ` Stephen Warren
2013-03-16 1:54 ` Bill Huang
2013-03-18 10:36 ` Ulf Hansson
2013-03-21 22:28 ` Mike Turquette
2013-03-16 2:23 ` Bill Huang
2013-03-15 17:12 ` Russell King - ARM Linux
2013-03-15 17:09 ` Russell King - ARM Linux
2013-03-16 2:25 ` Bill Huang
2013-03-15 16:59 ` Russell King - ARM Linux
2013-03-15 16:57 ` Russell King - ARM Linux
2013-03-15 18:44 ` Nicolas Pitre
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