From: Santosh Shilimkar <santosh.shilimkar-l0cyMroinI0@public.gmane.org>
To: Paul Walmsley <paul-DWxLp4Yu+b8AvxtiuMwx3w@public.gmane.org>
Cc: Felipe Balbi <balbi-l0cyMroinI0@public.gmane.org>,
Tony Lindgren <tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org>,
w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org,
linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org,
Linux OMAP Mailing List
<linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>,
Linux ARM Kernel Mailing List
<linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org>
Subject: Re: [PATCH] i2c: omap: ensure writes to dev->buf_len are ordered
Date: Sun, 28 Oct 2012 09:41:05 +0530 [thread overview]
Message-ID: <508CB059.8000203@ti.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210271545390.16409-rwI8Ez+7Ko+d5PgPZx9QOdBPR1lH4CV8@public.gmane.org>
On Saturday 27 October 2012 09:29 PM, Paul Walmsley wrote:
> On Sat, 27 Oct 2012, Santosh Shilimkar wrote:
>
>> Another alternative, which I will recommend to just make use of the
>> read*/wrire* instead __raw versions. The barriers are taken care
>> already and driver point of view, it is transparent.
>
> Those barriers will disappear if CONFIG_ARM_DMA_MEM_BUFFERABLE is set to
> N, so that's probably not the right thing to do in this case. The barrier
> here isn't DMA-related, it's needed due to the design of the driver.
>
Good point.
> In fact the wmb() is probably overkill, since only a compiler reordering
> barrier is needed. It can probably just be barrier().
>
I agree. Just barrier() is enough to avoid compiler re-ordering.
Regards
Santosh
WARNING: multiple messages have this Message-ID (diff)
From: santosh.shilimkar@ti.com (Santosh Shilimkar)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH] i2c: omap: ensure writes to dev->buf_len are ordered
Date: Sun, 28 Oct 2012 09:41:05 +0530 [thread overview]
Message-ID: <508CB059.8000203@ti.com> (raw)
In-Reply-To: <alpine.DEB.2.00.1210271545390.16409@utopia.booyaka.com>
On Saturday 27 October 2012 09:29 PM, Paul Walmsley wrote:
> On Sat, 27 Oct 2012, Santosh Shilimkar wrote:
>
>> Another alternative, which I will recommend to just make use of the
>> read*/wrire* instead __raw versions. The barriers are taken care
>> already and driver point of view, it is transparent.
>
> Those barriers will disappear if CONFIG_ARM_DMA_MEM_BUFFERABLE is set to
> N, so that's probably not the right thing to do in this case. The barrier
> here isn't DMA-related, it's needed due to the design of the driver.
>
Good point.
> In fact the wmb() is probably overkill, since only a compiler reordering
> barrier is needed. It can probably just be barrier().
>
I agree. Just barrier() is enough to avoid compiler re-ordering.
Regards
Santosh
next prev parent reply other threads:[~2012-10-28 4:11 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-10-25 9:00 [PATCH] i2c: omap: ensure writes to dev->buf_len are ordered Felipe Balbi
2012-10-25 9:00 ` Felipe Balbi
2012-10-25 16:38 ` Kevin Hilman
2012-10-25 16:38 ` Kevin Hilman
[not found] ` <8739124idt.fsf-1D3HCaltpLuhEniVeURVKkEOCMrvLtNR@public.gmane.org>
2012-10-25 18:03 ` Felipe Balbi
2012-10-25 18:03 ` Felipe Balbi
[not found] ` <1351155648-20429-1-git-send-email-balbi-l0cyMroinI0@public.gmane.org>
2012-10-25 9:16 ` Shubhrajyoti Datta
2012-10-25 9:16 ` Shubhrajyoti Datta
2012-10-26 23:01 ` Paul Walmsley
2012-10-26 23:01 ` Paul Walmsley
2012-10-27 10:50 ` Santosh Shilimkar
2012-10-27 10:50 ` Santosh Shilimkar
2012-10-27 15:59 ` Paul Walmsley
2012-10-27 15:59 ` Paul Walmsley
[not found] ` <alpine.DEB.2.00.1210271545390.16409-rwI8Ez+7Ko+d5PgPZx9QOdBPR1lH4CV8@public.gmane.org>
2012-10-28 4:11 ` Santosh Shilimkar [this message]
2012-10-28 4:11 ` Santosh Shilimkar
2012-11-01 22:23 ` Wolfram Sang
2012-11-01 22:23 ` Wolfram Sang
[not found] ` <20121101222316.GC22956-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-11-02 8:54 ` Felipe Balbi
2012-11-02 8:54 ` Felipe Balbi
[not found] ` <20121102085447.GE17063-S8G//mZuvNWo5Im9Ml3/Zg@public.gmane.org>
2012-11-05 8:04 ` [PATCH v2] " Felipe Balbi
2012-11-05 8:04 ` Felipe Balbi
2012-11-14 11:20 ` Wolfram Sang
2012-11-14 11:20 ` Wolfram Sang
[not found] ` <20121114112050.GG5954-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org>
2012-11-14 14:22 ` [PATCH v3] " Felipe Balbi
2012-11-14 14:22 ` Felipe Balbi
2012-11-14 16:46 ` Wolfram Sang
2012-11-14 16:46 ` Wolfram Sang
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=508CB059.8000203@ti.com \
--to=santosh.shilimkar-l0cymroini0@public.gmane.org \
--cc=balbi-l0cyMroinI0@public.gmane.org \
--cc=ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org \
--cc=linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=paul-DWxLp4Yu+b8AvxtiuMwx3w@public.gmane.org \
--cc=tony-4v6yS6AI5VpBDgjK7y7TUQ@public.gmane.org \
--cc=w.sang-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.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.