Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751256Ab3GSLBv (ORCPT ); Fri, 19 Jul 2013 07:01:51 -0400 Received: from pequod.mess.org ([46.65.169.142]:52100 "EHLO pequod.mess.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750741Ab3GSLBu (ORCPT ); Fri, 19 Jul 2013 07:01:50 -0400 Date: Fri, 19 Jul 2013 12:01:47 +0100 From: Sean Young To: Srinivas KANDAGATLA Cc: linux-media@vger.kernel.org, alipowski@interia.pl, Mauro Carvalho Chehab , linux-kernel@vger.kernel.org, srinivas.kandagatla@gmail.com Subject: Re: [PATCH v1 1/2] media: rc: Add user count to rc dev. Message-ID: <20130719110147.GA1104@pequod.mess.org> References: <1374223132-4924-1-git-send-email-srinivas.kandagatla@st.com> <1374223167-4980-1-git-send-email-srinivas.kandagatla@st.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374223167-4980-1-git-send-email-srinivas.kandagatla@st.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2283 Lines: 72 On Fri, Jul 19, 2013 at 09:39:27AM +0100, Srinivas KANDAGATLA wrote: > From: Srinivas Kandagatla > > This patch adds user count to rc_dev structure, the reason to add this > new member is to allow other code like lirc to open rc device directly. > In the existing code, rc device is only opened by input subsystem which > works ok if we have any input drivers to match. But in case like lirc > where there will be no input driver, rc device will be never opened. > > Having this user count variable will be useful to allow rc device to be > opened from code other than rc-main. > > Signed-off-by: Srinivas Kandagatla > --- > drivers/media/rc/rc-main.c | 11 +++++++++-- > include/media/rc-core.h | 1 + > 2 files changed, 10 insertions(+), 2 deletions(-) > > diff --git a/drivers/media/rc/rc-main.c b/drivers/media/rc/rc-main.c > index 1cf382a..e800b96 100644 > --- a/drivers/media/rc/rc-main.c > +++ b/drivers/media/rc/rc-main.c > @@ -702,15 +702,22 @@ EXPORT_SYMBOL_GPL(rc_keydown_notimeout); > static int ir_open(struct input_dev *idev) > { > struct rc_dev *rdev = input_get_drvdata(idev); > + int rval = 0; > > - return rdev->open(rdev); > + if (!rdev->users++) > + rval = rdev->open(rdev); > + > + if (rval) > + rdev->users--; > + > + return rval; This looks racey. Some locking is needed, I think rc_dev->lock should work fine for this. Here and in the lirc code path too. Sean > } > > static void ir_close(struct input_dev *idev) > { > struct rc_dev *rdev = input_get_drvdata(idev); > > - if (rdev) > + if (rdev && !--rdev->users) > rdev->close(rdev); > } > > diff --git a/include/media/rc-core.h b/include/media/rc-core.h > index 06a75de..b42016a 100644 > --- a/include/media/rc-core.h > +++ b/include/media/rc-core.h > @@ -101,6 +101,7 @@ struct rc_dev { > bool idle; > u64 allowed_protos; > u64 enabled_protocols; > + u32 users; > u32 scanmask; > void *priv; > spinlock_t keylock; > -- > 1.7.6.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/