From: Arnd Bergmann <arnd@arndb.de>
To: Michal Simek <monstr@monstr.eu>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>,
Grant Likely <grant.likely@secretlab.ca>,
Alexey Brodkin <Alexey.Brodkin@synopsys.com>,
Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Vineet Gupta <Vineet.Gupta1@synopsys.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Alan Cox <alan@lxorguk.ukuu.org.uk>,
dahinds@users.sourceforge.net
Subject: Re: [PATCH] drivers/block/xsysace - replace in(out)_8/in(out)_be16/in(out)_le16 with generic iowrite(read)8/16(be)
Date: Tue, 12 Feb 2013 11:26:10 +0000 [thread overview]
Message-ID: <201302121126.10288.arnd@arndb.de> (raw)
In-Reply-To: <CAHTX3dJUduUj1a5_xCfjVc0y3J4-zUKZrBpQTvSj=SVVz=gvsg@mail.gmail.com>
On Tuesday 12 February 2013, Michal Simek wrote:
> > In particular, ARM can run both big- and little-endian even though
> > big-endian is rarely used, so you need to know the endianess for
> > the device you are talking to rather than assume that it knows
> > what the CPU does at the time.
>
> For high performance IPs using accessors functions is still problematic
> because there will be performance regression it means that
> from my point of view there still should be any option to "setup"
> proper endians for the driver and it can't be setup at run-time.
I did not mean you have to use a run-time detection here, although
that is often the easiest solution. If you know the endianess of
a device for a specific architecture or platform, it is totally
fine to pick that endianess at compile-time and use e.g. the
readl_relaxed() accessors on ARM to give you the lowest access
latency.
Arnd
next prev parent reply other threads:[~2013-02-12 11:26 UTC|newest]
Thread overview: 90+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-29 16:02 [PATCH] drivers/block/xsysace - replace in(out)_8/in(out)_be16/in(out)_le16 with generic iowrite(read)8/16(be) Alexey Brodkin
2013-01-29 16:27 ` Arnd Bergmann
2013-01-30 11:03 ` Alexey Brodkin
2013-01-30 11:13 ` Michal Simek
2013-01-30 12:10 ` Vineet Gupta
2013-01-30 12:31 ` Michal Simek
2013-01-30 14:36 ` Arnd Bergmann
2013-02-04 9:26 ` Michal Simek
2013-02-04 17:24 ` Arnd Bergmann
2013-02-05 2:29 ` Benjamin Herrenschmidt
2013-02-05 10:54 ` Michal Simek
2013-02-05 12:09 ` Vineet Gupta
2013-02-05 12:29 ` Benjamin Herrenschmidt
2013-02-05 12:19 ` Benjamin Herrenschmidt
2013-02-05 12:38 ` Michal Simek
2013-02-05 14:03 ` Alexey Brodkin
2013-02-05 15:12 ` Arnd Bergmann
2013-02-05 21:01 ` Benjamin Herrenschmidt
2013-02-06 10:03 ` Grant Likely
2013-02-06 16:20 ` Arnd Bergmann
2013-02-06 16:21 ` Michal Simek
2013-02-07 0:34 ` Arnd Bergmann
2013-02-06 17:40 ` Michal Simek
2013-02-06 19:51 ` Geert Uytterhoeven
2013-02-07 7:23 ` Michal Simek
2013-02-07 7:38 ` Geert Uytterhoeven
2013-02-07 8:01 ` Michal Simek
2013-02-07 8:20 ` Geert Uytterhoeven
2013-02-07 8:33 ` Arnd Bergmann
2013-02-07 14:19 ` Michal Simek
2013-02-07 23:12 ` Arnd Bergmann
2013-02-11 10:38 ` Michal Simek
2013-02-11 15:26 ` Arnd Bergmann
2013-02-11 15:36 ` Michal Simek
2013-02-11 15:43 ` Arnd Bergmann
2013-02-11 15:57 ` Michal Simek
2013-02-11 16:08 ` Arnd Bergmann
2013-02-12 0:29 ` Benjamin Herrenschmidt
2013-02-12 11:29 ` Arnd Bergmann
2013-02-12 10:11 ` Michal Simek
2013-02-12 11:26 ` Arnd Bergmann [this message]
2013-02-12 12:14 ` Michal Simek
2013-02-12 13:55 ` Arnd Bergmann
2013-02-12 12:30 ` Benjamin Herrenschmidt
2013-02-12 0:25 ` Benjamin Herrenschmidt
2013-02-12 10:03 ` Michal Simek
2013-02-05 21:00 ` Benjamin Herrenschmidt
2013-02-05 21:25 ` Alexey Brodkin
2013-02-05 23:07 ` Benjamin Herrenschmidt
2013-02-06 10:14 ` Grant Likely
2013-02-06 16:27 ` Arnd Bergmann
2013-02-06 21:35 ` Benjamin Herrenschmidt
2013-02-07 12:09 ` Alexey Brodkin
2013-02-07 12:20 ` Benjamin Herrenschmidt
2013-02-07 12:23 ` Benjamin Herrenschmidt
2013-02-07 14:31 ` Michal Simek
2013-02-07 14:35 ` Alexey Brodkin
2013-02-07 14:39 ` Grant Likely
2013-02-07 14:51 ` Grant Likely
2013-02-07 15:12 ` Alexey Brodkin
2013-02-07 15:23 ` Grant Likely
2013-02-07 15:28 ` Alexey Brodkin
2013-02-07 16:44 ` Grant Likely
2013-02-07 16:56 ` Alexey Brodkin
2013-02-07 17:16 ` Grant Likely
2013-02-07 17:22 ` Alexey Brodkin
2013-02-08 7:45 ` Grant Likely
2013-02-07 21:18 ` Benjamin Herrenschmidt
2013-02-07 21:15 ` Benjamin Herrenschmidt
2013-02-07 23:05 ` Arnd Bergmann
2013-02-08 6:19 ` Geert Uytterhoeven
2013-02-08 7:14 ` Grant Likely
2013-02-07 21:09 ` Benjamin Herrenschmidt
2013-02-12 17:02 ` Michal Simek
2013-02-12 17:25 ` Arnd Bergmann
2013-03-21 17:01 ` Alexey Brodkin
2013-06-19 8:56 ` xsysace driver support on arches other than PPC/Microblaze Alexey Brodkin
2013-06-19 9:09 ` Alexey Brodkin
2013-06-19 12:13 ` Andy Shevchenko
2013-06-19 12:56 ` Alexey Brodkin
2013-06-19 14:51 ` Arnd Bergmann
2013-02-07 21:06 ` [PATCH] drivers/block/xsysace - replace in(out)_8/in(out)_be16/in(out)_le16 with generic iowrite(read)8/16(be) Benjamin Herrenschmidt
2013-02-05 23:03 ` Arnd Bergmann
2013-02-06 8:59 ` Geert Uytterhoeven
2013-02-06 16:18 ` Arnd Bergmann
2013-02-05 10:45 ` Michal Simek
-- strict thread matches above, loose matches on Subject: below --
2013-06-21 14:02 Alexey Brodkin
2013-06-21 14:23 ` Arnd Bergmann
2013-06-21 18:35 ` Alexey Brodkin
2013-06-21 18:40 ` Arnd Bergmann
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