From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from lb2-smtp-cloud2.xs4all.net ([194.109.24.25]:52131 "EHLO lb2-smtp-cloud2.xs4all.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751095AbdDAJWH (ORCPT ); Sat, 1 Apr 2017 05:22:07 -0400 Subject: Re: [PATCHv6 01/10] media: add CEC notifier support To: Russell King - ARM Linux References: <20170331122036.55706-1-hverkuil@xs4all.nl> <20170331122036.55706-2-hverkuil@xs4all.nl> <20170331204629.GV7909@n2100.armlinux.org.uk> Cc: linux-media@vger.kernel.org, Daniel Vetter , dri-devel@lists.freedesktop.org, linux-samsung-soc@vger.kernel.org, Krzysztof Kozlowski , Inki Dae , Marek Szyprowski , Javier Martinez Canillas , Benjamin Gaignard , Patrice.chotard@st.com, Hans Verkuil From: Hans Verkuil Message-ID: Date: Sat, 1 Apr 2017 11:22:03 +0200 MIME-Version: 1.0 In-Reply-To: <20170331204629.GV7909@n2100.armlinux.org.uk> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 31/03/17 22:46, Russell King - ARM Linux wrote: > On Fri, Mar 31, 2017 at 02:20:27PM +0200, Hans Verkuil wrote: >> +struct cec_notifier *cec_notifier_get(struct device *dev) >> +{ >> + struct cec_notifier *n; >> + >> + mutex_lock(&cec_notifiers_lock); >> + list_for_each_entry(n, &cec_notifiers, head) { >> + if (n->dev == dev) { >> + mutex_unlock(&cec_notifiers_lock); >> + kref_get(&n->kref); > > Isn't this racy? What stops one thread trying to get the notifier > while another thread puts the notifier? > Both get and put take the global cec_notifiers_lock mutex. Regards, Hans From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans Verkuil Subject: Re: [PATCHv6 01/10] media: add CEC notifier support Date: Sat, 1 Apr 2017 11:22:03 +0200 Message-ID: References: <20170331122036.55706-1-hverkuil@xs4all.nl> <20170331122036.55706-2-hverkuil@xs4all.nl> <20170331204629.GV7909@n2100.armlinux.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <20170331204629.GV7909@n2100.armlinux.org.uk> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Russell King - ARM Linux Cc: linux-samsung-soc@vger.kernel.org, Patrice.chotard@st.com, Krzysztof Kozlowski , Javier Martinez Canillas , Hans Verkuil , dri-devel@lists.freedesktop.org, Daniel Vetter , Marek Szyprowski , linux-media@vger.kernel.org List-Id: linux-samsung-soc@vger.kernel.org T24gMzEvMDMvMTcgMjI6NDYsIFJ1c3NlbGwgS2luZyAtIEFSTSBMaW51eCB3cm90ZToKPiBPbiBG cmksIE1hciAzMSwgMjAxNyBhdCAwMjoyMDoyN1BNICswMjAwLCBIYW5zIFZlcmt1aWwgd3JvdGU6 Cj4+ICtzdHJ1Y3QgY2VjX25vdGlmaWVyICpjZWNfbm90aWZpZXJfZ2V0KHN0cnVjdCBkZXZpY2Ug KmRldikKPj4gK3sKPj4gKwlzdHJ1Y3QgY2VjX25vdGlmaWVyICpuOwo+PiArCj4+ICsJbXV0ZXhf bG9jaygmY2VjX25vdGlmaWVyc19sb2NrKTsKPj4gKwlsaXN0X2Zvcl9lYWNoX2VudHJ5KG4sICZj ZWNfbm90aWZpZXJzLCBoZWFkKSB7Cj4+ICsJCWlmIChuLT5kZXYgPT0gZGV2KSB7Cj4+ICsJCQlt dXRleF91bmxvY2soJmNlY19ub3RpZmllcnNfbG9jayk7Cj4+ICsJCQlrcmVmX2dldCgmbi0+a3Jl Zik7Cj4gCj4gSXNuJ3QgdGhpcyByYWN5PyAgV2hhdCBzdG9wcyBvbmUgdGhyZWFkIHRyeWluZyB0 byBnZXQgdGhlIG5vdGlmaWVyCj4gd2hpbGUgYW5vdGhlciB0aHJlYWQgcHV0cyB0aGUgbm90aWZp ZXI/Cj4gCgpCb3RoIGdldCBhbmQgcHV0IHRha2UgdGhlIGdsb2JhbCBjZWNfbm90aWZpZXJzX2xv Y2sgbXV0ZXguCgpSZWdhcmRzLAoKCUhhbnMKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX18KZHJpLWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMu ZnJlZWRlc2t0b3Aub3JnCmh0dHBzOi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlz dGluZm8vZHJpLWRldmVsCg==