From: swarren@wwwdotorg•org (Stephen Warren)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] i2c: i2c-gpio: fix issue when DT node greater than 1
Date: Wed, 19 Sep 2012 09:28:04 -0600 [thread overview]
Message-ID: <5059E484.6090708@wwwdotorg.org> (raw)
In-Reply-To: <50591C9C.2080809@atmel.com>
On 09/18/2012 07:15 PM, Bo Shen wrote:
> Hi Stephen Warren,
>
> On 9/18/2012 22:51, Stephen Warren wrote:
>> On 09/18/2012 03:02 AM, Bo Shen wrote:
>>> When i2c-gpio node number is greater than 1, the second can not
>>> sucessfully
>>> regiter
>>>
>>> Using alias method to get the pdev->id, or else the second device
>>> will use
>>> the same id which will cause fail to register
>>
>> pdev->id shouldn't be used at all with device tree. Why does
>> registration fail without this change?
>
> I add the debug info, and it give the following error without this patch.
>
> --<8----------------------------------
> adap->name = i2c-gpio-1
> i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
> adap->name = i2c-gpio-1
> i2c-gpio: probe of i2c.3 failed with error -16
> -->8----------------------------------
>
> With this patch, it successfully registered.
> --<8----------------------------------
> adap->name = i2c-gpio0
> i2c-gpio i2c.2: using pins 30 (SDA) and 31 (SCL)
> adap->name = i2c-gpio1
> i2c-gpio i2c.3: using pins 90 (SDA) and 91 (SCL)
> -->8----------------------------------
Yes, that explains why the registration fails, but not why this patch is
the correct solution to the problem.
The problematic code appears to be:
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
Instead, I think that should be something more like:
adap->name = dev_name(&pdev->dev);
or perhaps:
if (pdev->dev.of_node)
/* named will be based on DT node name */
adap->name = dev_name(&pdev->dev);
else
snprintf(adap->name, sizeof(adap->name), "i2c-gpio%d", pdev->id);
?
next prev parent reply other threads:[~2012-09-19 15:28 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-18 9:02 [PATCH] i2c: i2c-gpio: fix issue when DT node greater than 1 Bo Shen
2012-09-18 14:51 ` Stephen Warren
2012-09-19 1:15 ` Bo Shen
2012-09-19 15:28 ` Stephen Warren [this message]
2012-09-19 15:54 ` Jean Delvare
2012-10-10 2:54 ` Bo Shen
2012-10-15 2:59 ` Bo Shen
2012-10-15 5:55 ` Jean-Christophe PLAGNIOL-VILLARD
2012-10-15 6:49 ` Jean Delvare
2012-10-15 7:32 ` Bo Shen
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=5059E484.6090708@wwwdotorg.org \
--to=swarren@wwwdotorg$(echo .)org \
--cc=linux-arm-kernel@lists$(echo .)infradead.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox