From: Arnd Bergmann <arnd@arndb.de>
To: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: linux-arm-kernel@lists.infradead.org,
Nicolas Ferre <nicolas.ferre@atmel.com>,
Boris Brezillon <boris.brezillon@free-electrons.com>,
Stephen Boyd <sboyd@codeaurora.org>,
linux-kernel@vger.kernel.org,
Cyrille Pitchen <cyrille.pitchen@atmel.com>,
Jean-Christophe Plagniol-Villard <plagnioj@jcrosoft.com>,
linux-clk@vger.kernel.org
Subject: Re: [PATCH 01/48] clk: at91: replace usleep() by udelay() calls
Date: Mon, 13 Jun 2016 21:26:49 +0200 [thread overview]
Message-ID: <6120818.MyeJZ74hYa@wuerfel> (raw)
In-Reply-To: <20160613152409.GD3240@piout.net>
On Monday, June 13, 2016 5:24:09 PM CEST Alexandre Belloni wrote:
> On 11/06/2016 at 00:30:36 +0200, Arnd Bergmann wrote :
> > On Saturday, June 11, 2016 12:03:04 AM CEST Alexandre Belloni wrote:
> > > From: Cyrille Pitchen <cyrille.pitchen@atmel.com>
> > >
> > > Fix the main and slow clock .prepare() implementations which used to call
> > > usleep() when the scheduler wasn't ready yet.
> > >
> >
> > Does this have to be called that early? It seems wasteful to always
> > call udelay() here, when these are functions that are normally
> > allowed to sleep.
> >
>
> So I've tested it and something like that would work:
>
> if (system_state < SYSTEM_RUNNING)
> udelay(osc->startup_usec);
> else
> usleep_range(osc->startup_usec, osc->startup_usec + 1);
I think that's reasonable in this case.
> But I'm afraid it would be the first driver to actually do something
> like that (however, it is already the only driver trying to sleep).
We have a lot of drivers that call potentially sleeping function from
the .prepare callback, e.g. when they go to an i2c controller.
Arnd
next prev parent reply other threads:[~2016-06-13 19:28 UTC|newest]
Thread overview: 75+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-10 22:03 [PATCH 00/48] ARM: at91: rework Atmel TCB drivers Alexandre Belloni
2016-06-10 22:03 ` [PATCH 01/48] clk: at91: replace usleep() by udelay() calls Alexandre Belloni
2016-06-10 22:30 ` Arnd Bergmann
2016-06-10 22:37 ` Alexandre Belloni
2016-06-13 15:24 ` Alexandre Belloni
2016-06-13 19:26 ` Arnd Bergmann [this message]
2016-06-14 16:05 ` Afzal Mohammed
2016-06-14 16:18 ` Boris Brezillon
2016-06-11 7:49 ` Boris Brezillon
2016-06-10 22:03 ` [PATCH 02/48] ARM: at91: Document new TCB bindings Alexandre Belloni
2016-06-14 21:47 ` Rob Herring
2016-06-15 7:29 ` Boris Brezillon
2016-06-21 20:08 ` Rob Herring
2016-06-21 20:28 ` Rob Herring
2016-06-10 22:03 ` [PATCH 03/48] ARM: dts: at91: at91rm9200: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 04/48] ARM: dts: at91: at91rm9200ek; use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 05/48] ARM: dts: at91: mpa1600; " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 06/48] ARM: dts: at91: at91sam9260: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 07/48] ARM: dts: at91: ethernut5: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 08/48] ARM: dts: at91: foxg20: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 09/48] ARM: dts: at91: animeo_ip: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 10/48] ARM: dts: at91: kizbox: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 11/48] ARM: dts: at91: at91sam9g20ek: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 12/48] ARM: dts: at91: ge863-pro3: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 13/48] ARM: dts: at91: at91sam9261: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 14/48] ARM: dts: at91: at91sam9261ek: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 15/48] ARM: dts: at91: at91sam9263: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 16/48] ARM: dts: at91: at91sam9263ek: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 17/48] ARM: dts: at91: calao: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 18/48] ARM: dts: at91: at91sam9g45: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 19/48] ARM: dts: at91: at91sam9m10g45ek: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 20/48] ARM: dts: at91: pm9g45: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 21/48] ARM: dts: at91: at91sam9rl: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 22/48] ARM: dts: at91: at91sam9rlek: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 23/48] ARM: dts: at91: at91sam9n12: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 24/48] ARM: dts: at91: at91sam9n12ek: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 25/48] ARM: dts: at91: at91sam9x5: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 26/48] ARM: dts: at91: at91sam9x5cm: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 27/48] ARM: dts: at91: acme/g25: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 28/48] ARM: dts: at91: cosino: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 29/48] ARM: dts: at91: kizboxmini: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 30/48] ARM: dts: at91: sama5d3: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 31/48] ARM: dts: at91: sama5d3xek; use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 32/48] ARM: dts: at91: sama5d3 Xplained: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 33/48] ARM: dts: at91: kizbox2: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 34/48] ARM: dts: at91: sama5d4: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 35/48] ARM: dts: at91: sama5d4: Add TCB2 Alexandre Belloni
2016-06-10 22:03 ` [PATCH 36/48] ARM: dts: at91: sama5d4ek: use TCB2 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 37/48] ARM: dts: at91: sama5d4 Xplained: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 38/48] ARM: dts: at91: ma5d4: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 39/48] ARM: dts: at91: vinco: " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 40/48] ARM: dts: at91: sama5d2: TC blocks are also simple-mfd and syscon devices Alexandre Belloni
2016-06-10 22:03 ` [PATCH 41/48] ARM: dts: at91: sama5d2 Xplained: use TCB0 as clocksource Alexandre Belloni
2016-06-10 22:03 ` [PATCH 42/48] clocksource/drivers: Add a new driver for the Atmel ARM TC blocks Alexandre Belloni
2016-06-11 12:48 ` Boris Brezillon
2016-06-22 13:07 ` Daniel Lezcano
2016-06-22 13:13 ` Boris Brezillon
2016-06-24 10:07 ` Daniel Lezcano
2017-05-16 11:59 ` Alexandre Belloni
2017-05-16 14:25 ` Daniel Lezcano
2017-05-16 14:35 ` Alexandre Belloni
2016-06-10 22:03 ` [PATCH 43/48] clocksource/drivers: Add a clockevent driver for Atmel " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 44/48] clocksource: atmel-pit: allow unselecting ATMEL_PIT Alexandre Belloni
2016-06-11 9:43 ` Thomas Gleixner
2016-06-11 10:53 ` Alexandre Belloni
2016-06-13 19:04 ` Boris Brezillon
2016-06-13 19:14 ` Thomas Gleixner
2016-06-16 14:41 ` Boris Brezillon
2016-06-10 22:03 ` [PATCH 45/48] ARM: at91/defconfig: sama5: unselect ATMEL_PIT Alexandre Belloni
2016-06-10 22:03 ` [PATCH 46/48] ARM: at91/defconfig: at91_dt " Alexandre Belloni
2016-06-10 22:03 ` [PATCH 47/48] PWM: atmel-tcb: switch to new binding Alexandre Belloni
2016-06-11 2:22 ` kbuild test robot
2016-06-10 22:03 ` [PATCH 48/48] ARM: dts: at91: kizbox: switch to new pwm-atmel-tcb binding Alexandre Belloni
2016-06-11 0:14 ` kbuild test robot
2016-06-11 10:25 ` Alexandre Belloni
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