From: Ben Dooks <ben-linux@fluff.org>
To: linux-arm-kernel@lists.infradead.org
Subject: Re: Locking in the clk API
Date: Thu, 20 Jan 2011 17:02:55 +0000 [thread overview]
Message-ID: <4D386ABF.9060908@fluff.org> (raw)
In-Reply-To: <AANLkTinHL9X_bqMPR=W8Va01O4xngUnpGCkCiE3xEdiQ@mail.gmail.com>
On 11/01/11 11:15, Richard Zhao wrote:
> 2011/1/11 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
[snip]
> A well running board will not enable/disable PLLs frequently. It don't
> make sense. PLLs are normally disabled on request to enter low power
> mode, rather not because all their child clocks are disabled. So we
> don't have to consider the time here.
I'd rather see that if all child clocks are disabled the PLL is
powered down then. It means PLLs _could_ be left running even
when power-down mode is selected because the system still thinks
that a peripheral is using them.
If you want to make it so that each low-power mode has to work
out what PLLs need to be disabled and then re-enabled makes me
want to be sick. Hiding this stuff behind specific implementations
is a recipe for disaster.
WARNING: multiple messages have this Message-ID (diff)
From: ben-linux@fluff.org (Ben Dooks)
To: linux-arm-kernel@lists.infradead.org
Subject: Locking in the clk API
Date: Thu, 20 Jan 2011 17:02:55 +0000 [thread overview]
Message-ID: <4D386ABF.9060908@fluff.org> (raw)
In-Reply-To: <AANLkTinHL9X_bqMPR=W8Va01O4xngUnpGCkCiE3xEdiQ@mail.gmail.com>
On 11/01/11 11:15, Richard Zhao wrote:
> 2011/1/11 Uwe Kleine-K?nig <u.kleine-koenig@pengutronix.de>:
[snip]
> A well running board will not enable/disable PLLs frequently. It don't
> make sense. PLLs are normally disabled on request to enter low power
> mode, rather not because all their child clocks are disabled. So we
> don't have to consider the time here.
I'd rather see that if all child clocks are disabled the PLL is
powered down then. It means PLLs _could_ be left running even
when power-down mode is selected because the system still thinks
that a peripheral is using them.
If you want to make it so that each low-power mode has to work
out what PLLs need to be disabled and then re-enabled makes me
want to be sick. Hiding this stuff behind specific implementations
is a recipe for disaster.
WARNING: multiple messages have this Message-ID (diff)
From: Ben Dooks <ben-linux@fluff.org>
To: Richard Zhao <linuxzsc@gmail.com>
Cc: "Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Lorenzo Pieralisi" <Lorenzo.Pieralisi@arm.com>,
"Russell King - ARM Linux" <linux@arm.linux.org.uk>,
linux-sh <linux-sh@vger.kernel.org>,
"Ben Herrenschmidt" <benh@kernel.crashing.org>,
"Sascha Hauer" <s.hauer@pengutronix.de>,
linux-kernel <linux-kernel@vger.kernel.org>,
"Vincent Guittot" <vincent.guittot@linaro.org>,
"Jeremy Kerr" <jeremy.kerr@canonical.com>,
linux-arm-kernel <linux-arm-kernel@lists.infradead.org>
Subject: Re: Locking in the clk API
Date: Thu, 20 Jan 2011 17:02:55 +0000 [thread overview]
Message-ID: <4D386ABF.9060908@fluff.org> (raw)
In-Reply-To: <AANLkTinHL9X_bqMPR=W8Va01O4xngUnpGCkCiE3xEdiQ@mail.gmail.com>
On 11/01/11 11:15, Richard Zhao wrote:
> 2011/1/11 Uwe Kleine-König <u.kleine-koenig@pengutronix.de>:
[snip]
> A well running board will not enable/disable PLLs frequently. It don't
> make sense. PLLs are normally disabled on request to enter low power
> mode, rather not because all their child clocks are disabled. So we
> don't have to consider the time here.
I'd rather see that if all child clocks are disabled the PLL is
powered down then. It means PLLs _could_ be left running even
when power-down mode is selected because the system still thinks
that a peripheral is using them.
If you want to make it so that each low-power mode has to work
out what PLLs need to be disabled and then re-enabled makes me
want to be sick. Hiding this stuff behind specific implementations
is a recipe for disaster.
next prev parent reply other threads:[~2011-01-20 17:02 UTC|newest]
Thread overview: 248+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-01-11 2:16 Locking in the clk API Jeremy Kerr
2011-01-11 2:16 ` Jeremy Kerr
2011-01-11 2:16 ` Jeremy Kerr
2011-01-11 3:15 ` Paul Mundt
2011-01-11 3:15 ` Paul Mundt
2011-01-11 3:15 ` Paul Mundt
2011-01-11 4:11 ` Jeremy Kerr
2011-01-11 4:11 ` Jeremy Kerr
2011-01-11 4:11 ` Jeremy Kerr
2011-01-11 4:54 ` Paul Mundt
2011-01-11 4:54 ` Paul Mundt
2011-01-11 4:54 ` Paul Mundt
2011-01-20 16:32 ` Ben Dooks
2011-01-20 16:32 ` Ben Dooks
2011-01-20 16:32 ` Ben Dooks
2011-01-20 18:57 ` Russell King - ARM Linux
2011-01-20 18:57 ` Russell King - ARM Linux
2011-01-20 18:57 ` Russell King - ARM Linux
2011-01-21 3:43 ` Saravana Kannan
2011-01-21 3:43 ` Saravana Kannan
2011-01-21 3:43 ` Saravana Kannan
2011-01-21 9:31 ` Russell King - ARM Linux
2011-01-21 9:31 ` Russell King - ARM Linux
2011-01-21 9:31 ` Russell King - ARM Linux
2011-01-11 9:03 ` Sascha Hauer
2011-01-11 9:03 ` Sascha Hauer
2011-01-11 9:03 ` Sascha Hauer
2011-01-11 9:28 ` Russell King - ARM Linux
2011-01-11 9:28 ` Russell King - ARM Linux
2011-01-11 9:28 ` Russell King - ARM Linux
2011-01-11 14:34 ` Pavel Machek
2011-01-11 14:34 ` Pavel Machek
2011-01-11 14:34 ` Pavel Machek
2011-01-20 16:29 ` Ben Dooks
2011-01-20 16:29 ` Ben Dooks
2011-01-20 16:29 ` Ben Dooks
2011-01-20 18:56 ` Russell King - ARM Linux
2011-01-20 18:56 ` Russell King - ARM Linux
2011-01-20 18:56 ` Russell King - ARM Linux
2011-01-20 21:30 ` Nicolas Pitre
2011-01-20 21:30 ` Nicolas Pitre
2011-01-20 21:30 ` Nicolas Pitre
2011-01-21 2:06 ` Dima Zavin
2011-01-21 2:06 ` Dima Zavin
2011-01-21 2:06 ` Dima Zavin
2011-01-21 4:12 ` Saravana Kannan
2011-01-21 4:12 ` Saravana Kannan
2011-01-21 4:12 ` Saravana Kannan
2011-01-21 9:32 ` Russell King - ARM Linux
2011-01-21 9:32 ` Russell King - ARM Linux
2011-01-21 9:32 ` Russell King - ARM Linux
2011-01-22 1:53 ` Saravana Kannan
2011-01-22 2:24 ` Colin Cross
2011-01-22 2:56 ` Saravana Kannan
2011-01-22 9:15 ` Russell King - ARM Linux
2011-01-24 19:31 ` Saravana Kannan
2011-01-21 21:03 ` Dima Zavin
2011-01-21 21:03 ` Dima Zavin
2011-01-21 21:03 ` Dima Zavin
2011-01-21 21:53 ` Nicolas Pitre
2011-01-21 21:53 ` Nicolas Pitre
2011-01-21 21:53 ` Nicolas Pitre
2011-01-21 22:02 ` Russell King - ARM Linux
2011-01-21 22:02 ` Russell King - ARM Linux
2011-01-21 22:02 ` Russell King - ARM Linux
2011-01-21 22:28 ` Colin Cross
2011-01-21 22:28 ` Colin Cross
2011-01-21 22:28 ` Colin Cross
2011-01-21 23:21 ` Benjamin Herrenschmidt
2011-01-21 23:21 ` Benjamin Herrenschmidt
2011-01-21 23:21 ` Benjamin Herrenschmidt
2011-01-21 23:50 ` Nicolas Pitre
2011-01-21 23:50 ` Nicolas Pitre
2011-01-21 23:50 ` Nicolas Pitre
2011-01-22 1:35 ` Saravana Kannan
2011-01-22 1:35 ` Saravana Kannan
2011-01-22 1:35 ` Saravana Kannan
2011-01-22 2:22 ` Colin Cross
2011-01-22 2:22 ` Colin Cross
2011-01-22 2:22 ` Colin Cross
2011-01-21 22:29 ` Nicolas Pitre
2011-01-21 22:29 ` Nicolas Pitre
2011-01-21 22:29 ` Nicolas Pitre
2011-01-21 23:28 ` Bryan Huntsman
2011-01-21 23:28 ` Bryan Huntsman
2011-01-21 23:28 ` Bryan Huntsman
2011-01-11 9:16 ` Russell King - ARM Linux
2011-01-11 9:16 ` Russell King - ARM Linux
2011-01-11 9:16 ` Russell King - ARM Linux
2011-01-11 9:44 ` Jeremy Kerr
2011-01-11 9:44 ` Jeremy Kerr
2011-01-11 9:44 ` Jeremy Kerr
2011-01-11 10:13 ` Paul Mundt
2011-01-11 10:13 ` Paul Mundt
2011-01-11 10:13 ` Paul Mundt
2011-01-11 10:30 ` Jeremy Kerr
2011-01-11 10:30 ` Jeremy Kerr
2011-01-11 10:30 ` Jeremy Kerr
2011-01-11 12:18 ` Paul Mundt
2011-01-11 12:18 ` Paul Mundt
2011-01-11 12:18 ` Paul Mundt
2011-01-11 13:52 `
2011-01-11 13:52 ` Uwe Kleine-König
2011-01-11 13:52 ` Uwe Kleine-König
2011-01-11 14:35 ` Jeremy Kerr
2011-01-11 14:35 ` Jeremy Kerr
2011-01-11 14:35 ` Jeremy Kerr
2011-01-12 3:25 ` Saravana Kannan
2011-01-12 3:25 ` Saravana Kannan
2011-01-12 3:25 ` Saravana Kannan
2011-01-12 7:40 `
2011-01-12 7:40 ` Uwe Kleine-König
2011-01-12 7:40 ` Uwe Kleine-König
2011-01-12 1:54 ` Saravana Kannan
2011-01-12 1:54 ` Saravana Kannan
2011-01-12 1:54 ` Saravana Kannan
2011-01-12 2:25 ` Paul Mundt
2011-01-12 2:25 ` Paul Mundt
2011-01-12 2:25 ` Paul Mundt
2011-01-20 16:57 ` Ben Dooks
2011-01-20 16:57 ` Ben Dooks
2011-01-20 16:57 ` Ben Dooks
2011-01-20 16:53 ` Ben Dooks
2011-01-20 16:53 ` Ben Dooks
2011-01-20 16:53 ` Ben Dooks
2011-01-20 16:40 ` Ben Dooks
2011-01-20 16:40 ` Ben Dooks
2011-01-20 16:40 ` Ben Dooks
2011-01-11 10:39 `
2011-01-11 10:39 ` Uwe Kleine-König
2011-01-11 10:39 ` Uwe Kleine-König
2011-01-11 10:47 ` Russell King - ARM Linux
2011-01-11 10:47 ` Russell King - ARM Linux
2011-01-11 10:47 ` Russell King - ARM Linux
2011-01-11 10:56 `
2011-01-11 10:56 ` Uwe Kleine-König
2011-01-11 10:56 ` Uwe Kleine-König
2011-01-11 11:15 ` Richard Zhao
2011-01-11 11:15 ` Richard Zhao
2011-01-11 11:15 ` Richard Zhao
2011-01-20 17:02 ` Ben Dooks [this message]
2011-01-20 17:02 ` Ben Dooks
2011-01-20 17:02 ` Ben Dooks
2011-01-20 19:08 ` Russell King - ARM Linux
2011-01-20 19:08 ` Russell King - ARM Linux
2011-01-20 19:08 ` Russell King - ARM Linux
2011-01-21 0:09 ` Jassi Brar
2011-01-21 0:09 ` Jassi Brar
2011-01-21 0:09 ` Jassi Brar
2011-01-21 4:47 ` Jassi Brar
2011-01-21 4:47 ` Jassi Brar
2011-01-21 4:47 ` Jassi Brar
2011-01-21 9:39 ` Russell King - ARM Linux
2011-01-21 9:39 ` Russell King - ARM Linux
2011-01-21 9:39 ` Russell King - ARM Linux
2011-01-21 10:11 ` Jassi Brar
2011-01-21 10:11 ` Jassi Brar
2011-01-21 10:11 ` Jassi Brar
2011-01-22 4:08 ` Richard Zhao
2011-01-22 4:08 ` Richard Zhao
2011-01-22 4:08 ` Richard Zhao
2011-01-22 5:30 ` Jassi Brar
2011-01-22 5:30 ` Jassi Brar
2011-01-22 5:30 ` Jassi Brar
2011-01-21 7:16 ` Saravana Kannan
2011-01-21 7:16 ` Saravana Kannan
2011-01-21 7:16 ` Saravana Kannan
2011-01-21 9:40 ` Russell King - ARM Linux
2011-01-21 9:40 ` Russell King - ARM Linux
2011-01-21 9:40 ` Russell King - ARM Linux
2011-01-22 1:47 ` Saravana Kannan
2011-01-27 4:34 ` Saravana Kannan
2011-01-27 4:34 ` Saravana Kannan
2011-01-27 4:34 ` Saravana Kannan
2011-01-27 8:54 ` Russell King - ARM Linux
2011-01-27 8:54 ` Russell King - ARM Linux
2011-01-27 8:54 ` Russell King - ARM Linux
2011-01-27 20:30 ` Saravana Kannan
2011-01-27 20:30 ` Saravana Kannan
2011-01-27 20:30 ` Saravana Kannan
2011-01-27 20:43 ` Russell King - ARM Linux
2011-01-27 20:43 ` Russell King - ARM Linux
2011-01-27 20:43 ` Russell King - ARM Linux
2011-01-27 21:07 ` Alan Cox
2011-01-27 21:07 ` Alan Cox
2011-01-27 21:07 ` Alan Cox
2011-01-27 21:11 ` Russell King - ARM Linux
2011-01-27 21:11 ` Russell King - ARM Linux
2011-01-27 21:11 ` Russell King - ARM Linux
2011-01-27 21:15 ` Russell King - ARM Linux
2011-01-27 21:15 ` Russell King - ARM Linux
2011-01-27 21:15 ` Russell King - ARM Linux
2011-01-28 3:29 ` Saravana Kannan
2011-01-28 3:29 ` Saravana Kannan
2011-01-28 3:29 ` Saravana Kannan
2011-01-28 3:27 ` Saravana Kannan
2011-01-28 3:27 ` Saravana Kannan
2011-01-28 3:27 ` Saravana Kannan
2011-01-11 12:11 ` Jassi Brar
2011-01-11 12:23 ` Jassi Brar
2011-01-11 12:11 ` Jassi Brar
2011-01-12 2:56 ` Saravana Kannan
2011-01-12 2:56 ` Saravana Kannan
2011-01-12 2:56 ` Saravana Kannan
2011-01-12 9:03 ` Russell King - ARM Linux
2011-01-12 9:03 ` Russell King - ARM Linux
2011-01-12 9:03 ` Russell King - ARM Linux
2011-01-15 14:02 ` Christer Weinigel
2011-01-15 14:02 ` Christer Weinigel
2011-01-15 14:02 ` Christer Weinigel
2011-01-15 14:53 ` Russell King - ARM Linux
2011-01-15 14:53 ` Russell King - ARM Linux
2011-01-15 14:53 ` Russell King - ARM Linux
2011-01-15 15:03 `
2011-01-15 15:03 ` Uwe Kleine-König
2011-01-15 15:03 ` Uwe Kleine-König
2011-01-15 15:15 ` Russell King - ARM Linux
2011-01-15 15:15 ` Russell King - ARM Linux
2011-01-15 15:15 ` Russell King - ARM Linux
2011-01-15 16:03 `
2011-01-15 16:03 ` Uwe Kleine-König
2011-01-15 16:03 ` Uwe Kleine-König
2011-01-15 16:21 ` Russell King - ARM Linux
2011-01-15 16:21 ` Russell King - ARM Linux
2011-01-15 16:21 ` Russell King - ARM Linux
2011-01-15 16:31 `
2011-01-15 16:31 ` Uwe Kleine-König
2011-01-15 16:31 ` Uwe Kleine-König
2011-01-16 6:59 ` Grant Likely
2011-01-16 6:59 ` Grant Likely
2011-01-16 6:59 ` Grant Likely
2011-01-15 17:07 ` Christer Weinigel
2011-01-15 17:07 ` Christer Weinigel
2011-01-15 17:07 ` Christer Weinigel
2011-01-15 17:20 ` Russell King - ARM Linux
2011-01-15 17:20 ` Russell King - ARM Linux
2011-01-15 17:20 ` Russell King - ARM Linux
2011-01-15 17:44 ` Christer Weinigel
2011-01-15 17:44 ` Christer Weinigel
2011-01-15 17:44 ` Christer Weinigel
2011-01-15 20:30 ` Russell King - ARM Linux
2011-01-15 20:30 ` Russell King - ARM Linux
2011-01-15 20:30 ` Russell King - ARM Linux
2011-01-17 1:19 ` Jeremy Kerr
2011-01-17 1:19 ` Jeremy Kerr
2011-01-17 1:19 ` Jeremy Kerr
2011-01-17 1:27 ` Jeremy Kerr
2011-01-17 1:27 ` Jeremy Kerr
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