From: Arnd Bergmann <arnd@arndb.de>
To: David Daney <ddaney@caviumnetworks.com>
Cc: David Daney <ddaney.cavm@gmail.com>,
linux-mips@linux-mips.org, ralf@linux-mips.org,
Jamie Iles <jamie@jamieiles.com>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>,
linux-serial@vger.kernel.org, linux-kernel@vger.kernel.org,
David Daney <david.daney@cavium.com>
Subject: Re: [PATCH 3/5] tty/8250_dw: Add support for OCTEON UARTS.
Date: Wed, 19 Jun 2013 20:52:09 +0200 [thread overview]
Message-ID: <201306192052.09575.arnd@arndb.de> (raw)
In-Reply-To: <51C1E028.2040700@caviumnetworks.com>
On Wednesday 19 June 2013, David Daney wrote:
> On 06/19/2013 03:01 AM, Arnd Bergmann wrote:
> > It's also wrong to use the
> > __raw_* variant, which is not guaranteed to be atomic and is not
> > endian-safe.
>
> We do runtime probing and only use this function on platforms where it
> is appropriate, so atomicity is not an issue. As for endianess, I used
> the __raw_ variant precisely because it is correct for both big and
> little endian kernels.
You don't know what the compiler turns a __raw_writeq into, it could
always to eight byte wise stores, that's why typically writeq is
an inline assembly while __raw_writeq is just a pointer dereference.
__raw_* never do endian swaps, so it will be wrong on either big-endian
CPUs or on little-endian CPUs, depending on what the MMIO register
needs.
Arnd
next prev parent reply other threads:[~2013-06-19 18:52 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-06-18 19:12 [PATCH 0/5] MIPS/tty/8250: Use standard 8250 drivers for OCTEON David Daney
2013-06-18 19:12 ` [PATCH 1/5] Revert "MIPS: Octeon: Fix build error if CONFIG_SERIAL_8250=n" David Daney
2013-06-18 19:12 ` [PATCH 2/5] MIPS: OCTEON: Set proper UART clock in internal device trees David Daney
2013-06-18 19:12 ` [PATCH 3/5] tty/8250_dw: Add support for OCTEON UARTS David Daney
2013-06-18 19:26 ` Greg Kroah-Hartman
2013-06-19 10:01 ` Arnd Bergmann
2013-06-19 10:52 ` Ralf Baechle
2013-06-19 16:45 ` David Daney
2013-06-19 16:45 ` David Daney
2013-06-19 18:52 ` Arnd Bergmann [this message]
2013-06-19 19:12 ` David Daney
2013-06-19 19:12 ` David Daney
2013-06-19 14:10 ` Heikki Krogerus
2013-06-19 16:47 ` David Daney
2013-06-18 19:12 ` [PATCH 4/5] MIPS: OCTEON: Remove custom serial setup code David Daney
2013-06-18 19:12 ` [PATCH 5/5] MIPS: Update cavium_octeon_defconfig David Daney
2013-06-18 19:26 ` [PATCH 0/5] MIPS/tty/8250: Use standard 8250 drivers for OCTEON Greg Kroah-Hartman
2013-06-18 19:36 ` Ralf Baechle
2013-06-18 19:59 ` David Daney
2013-06-18 19:59 ` David Daney
2013-06-18 21:28 ` Jamie Iles
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=201306192052.09575.arnd@arndb.de \
--to=arnd@arndb.de \
--cc=david.daney@cavium.com \
--cc=ddaney.cavm@gmail.com \
--cc=ddaney@caviumnetworks.com \
--cc=gregkh@linuxfoundation.org \
--cc=jamie@jamieiles.com \
--cc=jslaby@suse.cz \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@linux-mips.org \
--cc=linux-serial@vger.kernel.org \
--cc=ralf@linux-mips.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.