From: Russell King - ARM Linux <linux@armlinux.org.uk>
To: Finn Thain <fthain@telegraphics.com.au>
Cc: Christoph Hellwig <hch@infradead.org>,
Geert Uytterhoeven <geert@linux-m68k.org>,
Arnd Bergmann <arnd@arndb.de>,
Stephen N Chivers <schivers@csc.com.au>,
Thomas Gleixner <tglx@linutronix.de>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
John Stultz <john.stultz@linaro.org>,
linux-m68k@lists.linux-m68k.org, linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Subject: Re: [RFC PATCH 01/13] arm: Fix mutual exclusion in arch_gettimeoffset
Date: Tue, 13 Nov 2018 09:20:13 +0000 [thread overview]
Message-ID: <20181113092012.GI30658@n2100.armlinux.org.uk> (raw)
In-Reply-To: <alpine.LNX.2.21.1811131420150.362@nippy.intranet>
On Tue, Nov 13, 2018 at 02:39:00PM +1100, Finn Thain wrote:
> On Mon, 12 Nov 2018, Christoph Hellwig wrote:
>
> > On Mon, Nov 12, 2018 at 03:12:39PM +1100, Finn Thain wrote:
> > > Implementations of arch_gettimeoffset are generally not re-entrant and
> > > assume that interrupts have been disabled. Unfortunately this
> > > pre-condition got broken in v2.6.32.
> > >
> > > Fixes: 5cfc8ee0bb51 ("ARM: convert arm to arch_gettimeoffset()")
> > > Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
> >
> > This looks like a sensible fix for -stable backporting. But with m68k
> > converted over it might be time for these two arm platforms to either
> > be converted to the clocksource API or to be dropped..
> >
>
> You could remove the old arch_gettimeoffset API without dropping any
> platforms.
>
> If no-one converts a given platform to the clocksource API it would mean
> that the default 'jiffies' clocksource will get used on that platform.
>
> Clock resolution and timer precision would be degraded, but that might not
> matter.
>
> Anyway, if someone who has this hardware is willing to test a clocksource
> API conversion, they can let me know and I'll attempt that patch.
There's reasons why that's not appropriate - such as not having two
separate timers in order to supply a clocksource and separate clock
event.
Not all hardware is suited to the clocksource + clockevent idea.
--
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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next prev parent reply other threads:[~2018-11-13 9:20 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-11-12 4:12 [RFC PATCH 00/13] m68k: Drop arch_gettimeoffset and adopt clocksource API Finn Thain
2018-11-12 4:12 ` [RFC PATCH 08/13] m68k: atari: Convert to " Finn Thain
2018-11-12 4:12 ` [RFC PATCH 04/13] m68k: mac: Clean up unused timer definitions Finn Thain
2018-11-12 4:12 ` [RFC PATCH 10/13] m68k: hp300: Convert to clocksource API Finn Thain
2018-11-12 4:12 ` [RFC PATCH 11/13] m68k: mac: " Finn Thain
2018-11-12 4:12 ` [RFC PATCH 01/13] arm: Fix mutual exclusion in arch_gettimeoffset Finn Thain
2018-11-12 8:34 ` Christoph Hellwig
2018-11-13 3:39 ` Finn Thain
2018-11-13 9:20 ` Russell King - ARM Linux [this message]
2018-11-13 21:55 ` Finn Thain
2018-11-13 23:43 ` Russell King - ARM Linux
2018-11-14 1:35 ` Michael Schmitz
2018-11-14 7:58 ` Russell King - ARM Linux
2018-11-15 1:34 ` Michael Schmitz
2018-11-14 3:17 ` Finn Thain
2018-11-14 14:16 ` Russell King - ARM Linux
2018-11-14 14:58 ` Geert Uytterhoeven
2018-11-14 18:11 ` Russell King - ARM Linux
2018-11-15 4:12 ` Finn Thain
2018-11-16 17:47 ` Russell King - ARM Linux
2018-11-16 22:49 ` Finn Thain
2018-11-17 3:00 ` Michael Schmitz
2018-11-14 12:05 ` Russell King - ARM Linux
2018-11-12 4:12 ` [RFC PATCH 02/13] m68k: " Finn Thain
2018-11-12 4:12 ` [RFC PATCH 07/13] m68k: amiga: Convert to clocksource API Finn Thain
2018-11-12 9:02 ` Geert Uytterhoeven
2018-11-12 9:21 ` Finn Thain
2018-11-12 4:12 ` [RFC PATCH 09/13] m68k: bvme6000: " Finn Thain
2018-11-12 4:12 ` [RFC PATCH 06/13] m68k: Drop ARCH_USES_GETTIMEOFFSET Finn Thain
2018-11-12 9:00 ` Geert Uytterhoeven
2018-11-12 9:06 ` Finn Thain
2018-11-13 2:29 ` Michael Schmitz
2018-11-13 3:14 ` Finn Thain
2018-11-13 4:50 ` Michael Schmitz
2018-11-13 6:15 ` Finn Thain
2018-11-13 8:24 ` Michael Schmitz
2018-11-13 22:11 ` Finn Thain
2018-11-14 1:08 ` Michael Schmitz
2018-11-14 2:58 ` Michael Schmitz
2018-11-14 23:54 ` Michael Schmitz
2018-11-15 4:37 ` Finn Thain
2018-11-15 6:35 ` Michael Schmitz
2018-11-16 0:04 ` Finn Thain
2018-11-12 4:12 ` [RFC PATCH 13/13] m68k: mvme16x: Convert to clocksource API Finn Thain
2018-11-12 18:37 ` Thomas Gleixner
2018-11-13 0:11 ` Finn Thain
2018-11-13 22:04 ` Finn Thain
2018-11-13 22:10 ` [RFC PATCH 13/13] m68k: mvme16x: Convert to clocksource APIy Thomas Gleixner
2018-11-13 22:33 ` Finn Thain
2018-11-18 17:12 ` Thomas Gleixner
2018-11-12 4:12 ` [RFC PATCH 03/13] m68k: mac: Fix VIA timer counter accesses Finn Thain
2018-11-12 4:12 ` [RFC PATCH 12/13] m68k: mvme147: Convert to clocksource API Finn Thain
2018-11-12 4:12 ` [RFC PATCH 05/13] m68k: apollo, q40, sun3, sun3x: Remove arch_gettimeoffset implementations Finn Thain
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