linux-kernel - Re: [PATCH V3 10/11] ARM: remove struct sys

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Message-ID: <CACRpkdb-cmwTH_7EJO02m2+CCZrJ2ycgtGpf8stoiFKSm8jqww@mail.gmail.com>
Date:	Wed, 21 Nov 2012 09:28:12 +0100
From:	Linus Walleij <linus.walleij@...aro.org>
To:	Stephen Warren <swarren@...dotorg.org>
Cc:	Russell King <linux@....linux.org.uk>,
	Olof Johansson <olof@...om.net>, Arnd Bergmann <arnd@...db.de>,
	John Stultz <johnstul@...ibm.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	linux-arch@...r.kernel.org, Stephen Warren <swarren@...dia.com>,
	Jonas ABERG <jonas.aberg@...ricsson.com>
Subject: Re: [PATCH V3 10/11] ARM: remove struct sys_timer suspend and resume fields

Oh and there was this comment/TODO:

On Mon, Nov 19, 2012 at 7:31 PM, Stephen Warren <swarren@...dotorg.org> wrote:

> @@ -17,15 +17,6 @@
>   *   Initialise the kernels jiffy timer source, claim interrupt
>   *   using setup_irq.  This is called early on during initialisation
>   *   while interrupts are still disabled on the local CPU.
> - * - suspend
> - *   Suspend the kernel jiffy timer source, if necessary.  This
> - *   is called with interrupts disabled, after all normal devices
> - *   have been suspended.  If no action is required, set this to
> - *   NULL.
> - * - resume
> - *   Resume the kernel jiffy timer source, if necessary.  This
> - *   is called with interrupts disabled before any normal devices
> - *   are resumed.  If no action is required, set this to NULL.
>   * - offset
>   *   Return the timer offset in microseconds since the last timer
>   *   interrupt.  Note: this must take account of any unprocessed
> @@ -33,8 +24,6 @@
>   */
>  struct sys_timer {
>         void                    (*init)(void);
> -       void                    (*suspend)(void);
> -       void                    (*resume)(void);
>  };

So from the above it is quite clear that the sys_timer is breaking
the suspend_noirq/resume_noirq naming convention from
runtime PM as IRQs are disabled on these paths.

The same goes for struct clock_event_device ...

So while this looks just as bad after as before the patch,
we should take a mental notice to rename the .suspend
and .resume hooks in the clock_event_device to
.suspend_noirq and .resume_noirq at some point.

I was thinking that if your patch set is introducing a
plethora of new users of these hooks we should maybe
stick a patch at the beginning of the series renaming the
hooks to *_noirq, but if it's a major obstacle it can surely wait.

Yours,
Linus Walleij
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