From: Stephen Warren <swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
To: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Cc: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org,
Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>,
Phil Carmody
<phil.carmody-GrGkmOP51GdLN7c7dRTbYkEOCMrvLtNR@public.gmane.org>,
stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Subject: Re: [PATCH] i2c: Re-instate body of i2c_parent_is_i2c_adapter()
Date: Thu, 16 Jan 2014 10:25:31 -0700 [thread overview]
Message-ID: <52D8160B.7090205@wwwdotorg.org> (raw)
In-Reply-To: <20140114161254.GA6442@katana>
On 01/14/2014 09:12 AM, Wolfram Sang wrote:
> On Mon, Jan 13, 2014 at 02:29:04PM -0700, Stephen Warren wrote:
>> From: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>>
>> The body of i2c_parent_is_i2c_adapter() is currently guarded by
>> CONFIG_I2C_MUX instead.
>
> This paragraph sounds strange to me. I'll update it a little. After that
> I'll go looking for a brown paper bag...
>
>> Among potentially other problems, this resulted in i2c_lock_adapter()
>> only locking I2C mux child adapters, and not the parent adapter. In
>> turn, this could allow inter-mingling of mux child selection and I2C
>> transactions, which could result in I2C transactions being directed to
>> the wrong I2C bus, and possibly even switching between busses in the
>> middle of a transaction.
>>
>> One concrete issue caused by this bug was corrupted HDMI EDID reads
>> during boot on the NVIDIA Tegra Seaboard system, although this only
>> became apparent in recent linux-next, when the boot timing was changed
>> just enough to trigger the race condition.
>>
>> Fixes: 3923172b3d70 ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case")
>> Cc: Phil Carmody <phil.carmody-GrGkmOP51GdLN7c7dRTbYkEOCMrvLtNR@public.gmane.org>
>> Cc: <stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
>> Signed-off-by: Stephen Warren <swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org>
>
> Applied to for-current, thanks for catching this one!
I do see this in for-current, but it looks like that branch isn't part
of linux-next. Should it be, or perhaps for-current should be merged
into for-next?
WARNING: multiple messages have this Message-ID (diff)
From: Stephen Warren <swarren@wwwdotorg.org>
To: Wolfram Sang <wsa@the-dreams.de>
Cc: linux-i2c@vger.kernel.org, linux-kernel@vger.kernel.org,
Stephen Warren <swarren@nvidia.com>,
Phil Carmody <phil.carmody@partner.samsung.com>,
stable@vger.kernel.org
Subject: Re: [PATCH] i2c: Re-instate body of i2c_parent_is_i2c_adapter()
Date: Thu, 16 Jan 2014 10:25:31 -0700 [thread overview]
Message-ID: <52D8160B.7090205@wwwdotorg.org> (raw)
In-Reply-To: <20140114161254.GA6442@katana>
On 01/14/2014 09:12 AM, Wolfram Sang wrote:
> On Mon, Jan 13, 2014 at 02:29:04PM -0700, Stephen Warren wrote:
>> From: Stephen Warren <swarren@nvidia.com>
>>
>> The body of i2c_parent_is_i2c_adapter() is currently guarded by
>> CONFIG_I2C_MUX instead.
>
> This paragraph sounds strange to me. I'll update it a little. After that
> I'll go looking for a brown paper bag...
>
>> Among potentially other problems, this resulted in i2c_lock_adapter()
>> only locking I2C mux child adapters, and not the parent adapter. In
>> turn, this could allow inter-mingling of mux child selection and I2C
>> transactions, which could result in I2C transactions being directed to
>> the wrong I2C bus, and possibly even switching between busses in the
>> middle of a transaction.
>>
>> One concrete issue caused by this bug was corrupted HDMI EDID reads
>> during boot on the NVIDIA Tegra Seaboard system, although this only
>> became apparent in recent linux-next, when the boot timing was changed
>> just enough to trigger the race condition.
>>
>> Fixes: 3923172b3d70 ("i2c: reduce parent checking to a NOOP in non-I2C_MUX case")
>> Cc: Phil Carmody <phil.carmody@partner.samsung.com>
>> Cc: <stable@vger.kernel.org>
>> Signed-off-by: Stephen Warren <swarren@nvidia.com>
>
> Applied to for-current, thanks for catching this one!
I do see this in for-current, but it looks like that branch isn't part
of linux-next. Should it be, or perhaps for-current should be merged
into for-next?
next prev parent reply other threads:[~2014-01-16 17:25 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-01-13 21:29 [PATCH] i2c: Re-instate body of i2c_parent_is_i2c_adapter() Stephen Warren
2014-01-13 21:29 ` Stephen Warren
2014-01-14 16:12 ` Wolfram Sang
2014-01-16 17:25 ` Stephen Warren [this message]
2014-01-16 17:25 ` Stephen Warren
[not found] ` <52D8160B.7090205-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org>
2014-01-16 18:04 ` Wolfram Sang
2014-01-16 18:04 ` 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=52D8160B.7090205@wwwdotorg.org \
--to=swarren-3lzwwm7+weoh9zmkesr00q@public.gmane.org \
--cc=linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=phil.carmody-GrGkmOP51GdLN7c7dRTbYkEOCMrvLtNR@public.gmane.org \
--cc=stable-u79uwXL29TY76Z2rM5mHXA@public.gmane.org \
--cc=swarren-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org \
--cc=wsa-z923LK4zBo2bacvFa/9K2g@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.