From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
To: Gregory CLEMENT <gregory.clement@free-electrons.com>
Cc: Lior Amsalem <alior@marvell.com>, Andrew Lunn <andrew@lunn.ch>,
Ike Pan <ike.pan@canonical.com>,
Nadav Haklai <nadavh@marvell.com>,
Ian Molton <ian.molton@codethink.co.uk>,
David Marlin <dmarlin@redhat.com>,
Yehuda Yitschak <yehuday@marvell.com>,
Jani Monoses <jani.monoses@canonical.com>,
Russell King <linux@arm.linux.org.uk>,
Tawfik Bayouk <tawfik@marvell.com>,
Dan Frazier <dann.frazier@canonical.com>,
Eran Ben-Avi <benavi@marvell.com>,
Leif Lindholm <leif.lindholm@arm.com>,
Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>,
Jason Cooper <jason@lakedaemon.net>,
Arnd Bergmann <arnd@arndb.de>, Jon Masters <jcm@redhat.com>,
Rob Herring <rob.herring@calxeda.com>,
Ben Dooks <ben-linux@fluff.org>,
linux-arm-kernel@lists.infradead.org,
Chris Van Hoof <vanhoof@canonical.com>,
Nicolas Pitre <nico@fluxnic.net>,
linux-kernel@vger.kernel.org, Maen Suleiman <maen@marvell.com>,
Shadi Ammouri <shadi@marvell.com>,
Olof Johansson <olof@lixom.net>
Subject: Re: [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support
Date: Wed, 24 Oct 2012 16:56:02 +0200 [thread overview]
Message-ID: <20121024165602.631f070b@skate> (raw)
In-Reply-To: <5087FD91.1050803@free-electrons.com>
Dear Gregory CLEMENT,
On Wed, 24 Oct 2012 16:39:13 +0200, Gregory CLEMENT wrote:
> > As others said, the prefix is wrong. Since the file is named coherency,
> > maybe just "coherency_" as the prefix? Not sure, though. Shouldn't the
> > file be named coherency-armada-370-xp.c, as we have done for the irq
> > controller file? In that case, the armada_370_xp prefix would make
> > sense
>
> I would prefer to just use coherency_ everywhere and keep the name of
> the file as is. It made sense to suffix the irq file with
> armada-370-xp because the other mvebu SoCs have their own irq
> controller. Whereas, as far as I know the coherency unit is only
> present in the Armada 370/XP.
Well your argumentation may also be seen as an argument to name it
coherency-armada-370-xp.c :-) I don't have a strong opinion on this
though, and we can always rename it later if needed.
> >> int armada_xp_get_cpu_count(void)
> >> {
> >> int reg, cnt;
> >
> > static?
>
> Which function?
> armada_xp_get_cpu_count and armada_370_xp_set_cpu_coherent are exported
> and moreover are not part of this patch set but the SMP one.
Ok, then maybe this function shouldn't be between the DMA operations
implementation and the bus notifier callback.
> Yes indeed code in headsmp.S and armada_xp_smp_prepare_cpus() are
> redundant we can simplify it. I will change it in the SMP series and
> for this series also.
Great, thanks!
> > Do we have a good reason for having
> > armada_370_xp_coherency_iocache_init() separate from
> > armada_370_xp_coherency_iocache_init() ? I.e, what prevents us from
>
> No good reason because they are the same! ;)
Oops, indeed. but I see that you fixed the problem.
> But more seriously, armada_370_xp_coherency_init() is called as an
> early_init call whereas armada_370_xp_coherency_iocache_init() is called
> later by armada_370_xp_dt_init(). I have to check if we can use
> bus_register_notifier() from an early_init call or if we still need to
> call armada_370_xp_coherency_init() as an early_init call.
The early_initcall() is mandatory, see the comment on top of it:
+/* Coherency initialization have to be done before the SMP
+ * initialization of the CPUs*/
+early_initcall(armada_370_xp_coherency_init);
(BTW, there is a missing space between CPUs and the comment terminator).
So, my point was more: is it possible to register the bus notifier
as early as inside an early_initcall() callback.
Best regards,
Thomas
--
Thomas Petazzoni, Free Electrons
Kernel, drivers, real-time and embedded Linux
development, consulting, training and support.
http://free-electrons.com
prev parent reply other threads:[~2012-10-24 14:56 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-24 8:03 [PATCH 0/2] Add hardware I/O coherency support for Armada 370/XP Gregory CLEMENT
2012-10-24 8:04 ` [PATCH 1/2] arm: plat-orion: Add coherency attribute when setup mbus target Gregory CLEMENT
2012-10-24 11:55 ` Thomas Petazzoni
2012-10-24 8:04 ` [PATCH 2/2] arm: mvebu: Add hardware I/O Coherency support Gregory CLEMENT
2012-10-24 8:11 ` Yehuda Yitschak
2012-10-24 11:36 ` Arnd Bergmann
2012-10-24 11:48 ` Gregory CLEMENT
2012-10-24 11:53 ` Gregory CLEMENT
2012-10-24 12:24 ` Arnd Bergmann
2012-10-24 13:56 ` Gregory CLEMENT
2012-10-24 20:30 ` Arnd Bergmann
[not found] ` <20121024082529.GZ11837@lunn.ch>
2012-10-24 11:50 ` Gregory CLEMENT
2012-10-24 12:27 ` Thomas Petazzoni
2012-10-24 14:39 ` Gregory CLEMENT
2012-10-24 14:56 ` Thomas Petazzoni [this message]
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