From: nicolas.ferre@atmel•com (Nicolas Ferre)
To: linux-arm-kernel@lists•infradead.org
Subject: [PATCH] mtd: atmel_nand: fix bug driver will in a dead lock if no nand detected
Date: Wed, 13 Nov 2013 11:33:59 +0100 [thread overview]
Message-ID: <52835597.2010802@atmel.com> (raw)
In-Reply-To: <20131113084418.GA16999@norris.computersforpeace.net>
On 13/11/2013 09:44, Brian Norris :
> Hi Josh,
>
> On Wed, Nov 13, 2013 at 11:26:28AM +0800, Josh Wu wrote:
>> On 11/13/2013 8:10 AM, Brian Norris wrote:
>>> On Fri, Nov 08, 2013 at 11:46:30AM +0800, Josh Wu wrote:
>>>> On 11/8/2013 2:09 AM, Brian Norris wrote:
>>>>> if (nand_nfc.is_initialized) {
>>>>> ...
>>>> Yes, exactly.
>>>> And the NAND probe will also load the NFC device before it reach
>>>> above check code.
>>> No, it loads the *driver*, not the *device*. I'm not familiar with the
>>> driver core guarantees, but I don't think you can guarantee that just
>>> because a driver was registered before another that the corresponding
>>> devices will be probed in that order. Or are you relying on the
>>> dependencies captured by device tree? (I don't think even the
>>> parent/child dependency between NAND/NFC gives you enough.)
>>
>> I put more code here to make it clearer:
>>
>> arch/arm/boot/dts/sama5d3.dtsi:
>> nand0: nand at 60000000 {
>> compatible = "atmel,at91rm9200-nand";
>> ...
>> ranges;
>> ...
>> nfc at 70000000 {
>> compatible = "atmel,sama5d3-nfc";
>> ...
>> };
>> };
>
> Ah, so you're focusing purely on the device tree support? It seems this
> driver also supports traditional platform devices, but nobody uses NFC
> without DT? That explains some things.
Absolutely: the NFC is only available on SoC that are pure-DT.
The traditional platform device support is for older SoC that can use
this driver but do not have the NFC.
I let Josh continue the discussion on the registration topic.
[..]
Bye,
--
Nicolas Ferre
next prev parent reply other threads:[~2013-11-13 10:33 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-05 9:59 [PATCH] mtd: atmel_nand: fix bug driver will in a dead lock if no nand detected Josh Wu
2013-11-07 8:39 ` Brian Norris
2013-11-07 10:26 ` Josh Wu
2013-11-07 10:55 ` Nicolas Ferre
2013-11-07 18:09 ` Brian Norris
2013-11-08 3:46 ` Josh Wu
2013-11-13 0:10 ` Brian Norris
2013-11-13 3:26 ` Josh Wu
2013-11-13 8:44 ` Brian Norris
2013-11-13 10:33 ` Nicolas Ferre [this message]
2013-11-07 18:43 ` Brian Norris
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=52835597.2010802@atmel.com \
--to=nicolas.ferre@atmel$(echo .)com \
--cc=linux-arm-kernel@lists$(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