From: Jonathan Cameron <jic23@kernel.org>
To: "Zubair Lutfullah :" <zubair.lutfullah@gmail.com>
Cc: Dmitry Torokhov <dmitry.torokhov@gmail.com>,
linux-iio@vger.kernel.org, linux-input@vger.kernel.org,
linux-kernel@vger.kernel.org, bigeasy@linutronix.de,
gregkh@linuxfoundation.org
Subject: Re: [PATCH 2/2] iio: ti_am335x_adc: Add continuous sampling support
Date: Thu, 19 Sep 2013 06:33:37 +0100 [thread overview]
Message-ID: <39ea39e8-2d11-4c84-ac49-33fdcfa870ed@email.android.com> (raw)
In-Reply-To: <20130919051611.GA4363@gmail.com>
"Zubair Lutfullah :" <zubair.lutfullah@gmail.com> wrote:
>On Wed, Sep 18, 2013 at 06:05:12PM +0100, Jonathan Cameron wrote:
>>
>> >> >However in this case such conversion us dangerous. With all but
>IRQ
>> >> >resource managed by the traditional methods they will be released
>> >first
>> >> >with IRQ handler deregistered very last. Therefore if device is
>not
>> >> >properly quiesced IRQ raised during driver unbinding is likely to
>> >> >result
>> >> >in kernel oops.
>> >> >
>> >> >IOW devm_request_irq() is very often evil (it is still useful if
>> >_all_
>> >> >your resources are managed by devm_*).
>> >> >
>> >> >In case of your driver I'd recommend switching to
>> >> >request_irq()/free_irq() instead.
>> >> >
>> >> >Thanks.
>> >>
>> >> Pretty much all resources are devm managed in here
>> >>
>> >>
>>
>>https://git.kernel.org/cgit/linux/kernel/git/jic23/iio.git/tree/drivers/iio/adc/ti_am335x_adc.c?h=togreg&id=7a1aeba7ed0d5a1e83fd5a8ee2a2869430d40347
>> >
>> >
>> >So we are guaranteed that that new kfifo that is being allocated
>just
>> >before we requesting IRQ and will be freed way before we free the
>IRQ
>> >will not be used by the IOTQ handler?
>> >
>> >Thanks.
>> Good point. I forgot about that. The source of interrupts 'should'
>be disabled before the kfifo is freed but I guess perhaps better to
>play it safe. Would take a fair bit of review to be sure that is not
>going to cause grief.
>>
>> A few more devm handlers need writing before it is truly useful here.
>>
>> Thanks for pointing this out.
>>
>> J
>
>If I understand the conclusion correctly, no devm here?
No devm for the irq. The rest are fine.
>
>Zubair
>--
>To unsubscribe from this list: send the line "unsubscribe linux-iio" in
>the body of a message to majordomo@vger.kernel.org
>More majordomo info at http://vger.kernel.org/majordomo-info.html
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
next prev parent reply other threads:[~2013-09-19 5:33 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-09-17 4:44 [PATCH V9 0/2] iio: input: " Zubair Lutfullah
2013-09-17 4:44 ` [PATCH 1/2] input: ti_am335x_tsc: Enable shared IRQ for TSC Zubair Lutfullah
2013-09-17 4:44 ` [PATCH 2/2] iio: ti_am335x_adc: Add continuous sampling support Zubair Lutfullah
2013-09-18 4:27 ` Dmitry Torokhov
2013-09-18 6:54 ` Zubair Lutfullah :
2013-09-18 9:39 ` Jonathan Cameron
2013-09-18 11:25 ` Zubair Lutfullah :
2013-09-18 14:15 ` Dmitry Torokhov
2013-09-18 16:12 ` Jonathan Cameron
2013-09-18 16:24 ` Dmitry Torokhov
2013-09-18 17:05 ` Jonathan Cameron
2013-09-19 5:16 ` Zubair Lutfullah :
2013-09-19 5:33 ` Jonathan Cameron [this message]
-- strict thread matches above, loose matches on Subject: below --
2013-09-18 11:23 [PATCH V10 0/2] iio: input: " Zubair Lutfullah
2013-09-18 11:23 ` [PATCH 2/2] iio: " Zubair Lutfullah
2013-09-18 13:58 ` Jonathan Cameron
2013-09-19 5:24 ` Zubair Lutfullah :
2013-09-19 5:41 ` Jonathan Cameron
2013-09-19 5:55 ` Zubair Lutfullah :
2013-09-01 11:17 [PATCH V8 0/2] iio: input: ti_am335x_tscadc: Add continuous sampling support to adc Zubair Lutfullah
2013-09-01 11:17 ` [PATCH 2/2] iio: ti_am335x_adc: Add continuous sampling support Zubair Lutfullah
2013-09-08 13:42 ` Jonathan Cameron
2013-09-11 16:02 ` Zubair Lutfullah :
2013-09-01 11:07 [PATCH V7 0/2] iio: input: ti_am335x_tscadc: Add continuous sampling support to adc Zubair Lutfullah
2013-09-01 11:07 ` [PATCH 2/2] iio: ti_am335x_adc: Add continuous sampling support Zubair Lutfullah
2013-08-25 22:45 [PATCH V6 0/2] iio: input: " Zubair Lutfullah
2013-08-25 22:45 ` [PATCH 2/2] iio: " Zubair Lutfullah
2013-08-27 8:42 ` Lee Jones
2013-08-28 13:01 ` Sebastian Andrzej Siewior
2013-08-28 18:43 ` Zubair Lutfullah :
2013-08-28 14:18 ` Sebastian Andrzej Siewior
2013-08-28 18:22 ` Zubair Lutfullah :
2013-08-28 16:43 ` Sebastian Andrzej Siewior
2013-08-28 18:19 ` Zubair Lutfullah :
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=39ea39e8-2d11-4c84-ac49-33fdcfa870ed@email.android.com \
--to=jic23@kernel.org \
--cc=bigeasy@linutronix.de \
--cc=dmitry.torokhov@gmail.com \
--cc=gregkh@linuxfoundation.org \
--cc=linux-iio@vger.kernel.org \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=zubair.lutfullah@gmail.com \
/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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
Powered by JetHome