From: Antonio Ospite <ao2@ao2.it>
To: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Cc: Alexey Khoroshilov <khoroshilov@ispras.ru>,
linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
ldv-project@linuxtesting.org, Daniel Ribeiro <drwyrm@gmail.com>,
Ilya Petrov <ilya.muromec@gmail.com>,
Antonio Ospite <ospite@studenti.unina.it>
Subject: Re: [PATCH] input: pcap2: avoid calling mutex_lock() in irq handler
Date: Sun, 6 Apr 2014 23:37:44 +0200 [thread overview]
Message-ID: <20140406233744.c40387e9bead51ee48e5ebd1@ao2.it> (raw)
In-Reply-To: <20140406202436.GA16739@core.coreip.homeip.net>
On Sun, 6 Apr 2014 13:24:36 -0700
Dmitry Torokhov <dmitry.torokhov@gmail.com> wrote:
> On Sun, Apr 06, 2014 at 12:54:50AM +0400, Alexey Khoroshilov wrote:
> > pcap_keys_handler() calls ezx_pcap_read() that calls mutex_lock().
> > pcap_keys_handler() is registered as nonthreaded irq handler,
> > that means sleeping function is called in irq handler.
> >
> > The patch makes a switch to threaded irq handling.
> > Compile tested only.
> >
> > Found by Linux Driver Verification project (linuxtesting.org).
> >
> > Signed-off-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
> > ---
> > drivers/input/misc/pcap_keys.c | 10 ++++++----
> > 1 file changed, 6 insertions(+), 4 deletions(-)
> >
> > diff --git a/drivers/input/misc/pcap_keys.c b/drivers/input/misc/pcap_keys.c
> > index cd230365166e..2a10f3a30969 100644
> > --- a/drivers/input/misc/pcap_keys.c
> > +++ b/drivers/input/misc/pcap_keys.c
> > @@ -79,13 +79,15 @@ static int pcap_keys_probe(struct platform_device *pdev)
> > if (err)
> > goto fail_allocate;
> >
> > - err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
> > - pcap_keys_handler, 0, "Power key", pcap_keys);
> > + err = request_threaded_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_ONOFF),
> > + NULL, pcap_keys_handler, 0,
> > + "Power key", pcap_keys);
> > if (err)
> > goto fail_register;
> >
> > - err = request_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
> > - pcap_keys_handler, 0, "Headphone button", pcap_keys);
> > + err = request_threaded_irq(pcap_to_irq(pcap_keys->pcap, PCAP_IRQ_MIC),
> > + NULL, pcap_keys_handler, 0,
> > + "Headphone button", pcap_keys);
>
> So I guess we do need threaded IRQ here, but I do not see the pcap's
> irqchip specifying IRQCHIP_ONESHOT_SAFE so I do not think
> request_threaded_irq() without IRQF_ONESHOT would succeed.
>
> Can someone test the change to be sure?
>
I can try to test it in a couple of weeks, I don't have the hardware
at hand right now.
Ciao,
Antonio
--
Antonio Ospite
http://ao2.it
A: Because it messes up the order in which people normally read text.
See http://en.wikipedia.org/wiki/Posting_style
Q: Why is top-posting such a bad thing?
next prev parent reply other threads:[~2014-04-06 21:37 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-04-05 20:54 [PATCH] input: pcap2: avoid calling mutex_lock() in irq handler Alexey Khoroshilov
2014-04-06 20:24 ` Dmitry Torokhov
2014-04-06 21:37 ` Antonio Ospite [this message]
2014-05-13 2:14 ` Dmitry Torokhov
2014-05-13 8:13 ` Antonio Ospite
2014-05-21 9:17 ` Antonio Ospite
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=20140406233744.c40387e9bead51ee48e5ebd1@ao2.it \
--to=ao2@ao2.it \
--cc=dmitry.torokhov@gmail.com \
--cc=drwyrm@gmail.com \
--cc=ilya.muromec@gmail.com \
--cc=khoroshilov@ispras.ru \
--cc=ldv-project@linuxtesting.org \
--cc=linux-input@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ospite@studenti.unina.it \
/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;
as well as URLs for NNTP newsgroup(s).