From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dawid Kurek Subject: Re: [PATCH] drm: Reduce scope of 'state' variable Date: Thu, 15 Jun 2017 16:24:30 +0200 Message-ID: <20170615142430.GA13398@gmail.com> References: <20170615104142.GA29276@gmail.com> <871sqlzewc.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: base64 Return-path: Received: from mail-lf0-x242.google.com (mail-lf0-x242.google.com [IPv6:2a00:1450:4010:c07::242]) by gabe.freedesktop.org (Postfix) with ESMTPS id 84BBA6E79A for ; Thu, 15 Jun 2017 14:24:38 +0000 (UTC) Received: by mail-lf0-x242.google.com with SMTP id u62so1595650lfg.0 for ; Thu, 15 Jun 2017 07:24:38 -0700 (PDT) Content-Disposition: inline In-Reply-To: <871sqlzewc.fsf@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" To: Jani Nikula Cc: Daniel Vetter , linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org List-Id: dri-devel@lists.freedesktop.org T24gMTUvMDYvMTcsIEphbmkgTmlrdWxhIHdyb3RlOgo+IE9uIFRodSwgMTUgSnVuIDIwMTcsIERh d2lkIEt1cmVrIDxkYXdpa3VyQGdtYWlsLmNvbT4gd3JvdGU6Cj4gPiBTbWFsbGVyIHNjb3BlIHJl ZHVjZXMgdmlzaWJpbGl0eSBvZiB2YXJpYWJsZSBhbmQgbWFrZXMgdXNhZ2Ugb2YKPiA+IHVuaW5p dGlhbGl6ZWQgdmFyaWFibGUgbGVzcyBwb3NzaWJsZS4KPiA+IC0tLQo+ID4gIGRyaXZlcnMvZ3B1 L2RybS9kcm1fYXRvbWljLmMgfCA1ICsrKy0tCj4gPiAgMSBmaWxlIGNoYW5nZWQsIDMgaW5zZXJ0 aW9ucygrKSwgMiBkZWxldGlvbnMoLSkKPiA+Cj4gPiBkaWZmIC0tZ2l0IGEvZHJpdmVycy9ncHUv ZHJtL2RybV9hdG9taWMuYyBiL2RyaXZlcnMvZ3B1L2RybS9kcm1fYXRvbWljLmMKPiA+IGluZGV4 IGYzMjUwNmEuLmVhNWE5YTcgMTAwNjQ0Cj4gPiAtLS0gYS9kcml2ZXJzL2dwdS9kcm0vZHJtX2F0 b21pYy5jCj4gPiArKysgYi9kcml2ZXJzL2dwdS9kcm0vZHJtX2F0b21pYy5jCj4gPiBAQCAtMTA4 LDEwICsxMDgsMTEgQEAgc3RydWN0IGRybV9hdG9taWNfc3RhdGUgKgo+ID4gIGRybV9hdG9taWNf c3RhdGVfYWxsb2Moc3RydWN0IGRybV9kZXZpY2UgKmRldikKPiA+ICB7Cj4gPiAgCXN0cnVjdCBk cm1fbW9kZV9jb25maWcgKmNvbmZpZyA9ICZkZXYtPm1vZGVfY29uZmlnOwo+ID4gLQlzdHJ1Y3Qg ZHJtX2F0b21pY19zdGF0ZSAqc3RhdGU7Cj4gPiAgCj4gPiAgCWlmICghY29uZmlnLT5mdW5jcy0+ YXRvbWljX3N0YXRlX2FsbG9jKSB7Cj4gPiAtCQlzdGF0ZSA9IGt6YWxsb2Moc2l6ZW9mKCpzdGF0 ZSksIEdGUF9LRVJORUwpOwo+ID4gKwkJc3RydWN0IGRybV9hdG9taWNfc3RhdGUgKnN0YXRlCj4g PiArCQkJPSBremFsbG9jKHNpemVvZigqc3RhdGUpLCBHRlBfS0VSTkVMKTsKPiAKPiBTZXBhcmF0 ZSBkZWNsYXJhdGlvbiBhbmQgaW5pdGlhbGl6YXRpb24gd291bGQgbGVhZCB0byBhIGNsZWFuZXIg cGF0Y2gKPiBhbmQgcmVzdWx0LgoKSSBzYXcgY29tYmluaW5nIGRlY2xhcmF0aW9uIGFuZCBpbml0 aWFsaXphdGlvbiBpcyBxdWl0ZSBjb21tb24sIGkuZS4gaW4KZHJtX2F0b21pYyBmaWxlLiBQZXJz b25hbGx5LCBJIGFsc28gcHJlZmVyIHRob3NlIGluIG9uZSBzdGF0ZW1lbnQuIEJ1dCB5ZXMsIGl0 Cmxvb2tzIGNsZWFuZXIgaGVyZSwgaW4gdHdvIGxpbmVzLgoKdjIgc2VudCA6KQoKVGhhbmtzLApE YXdpZAoKPiAKPiBCUiwKPiBKYW5pLgo+IAo+ID4gKwo+ID4gIAkJaWYgKCFzdGF0ZSkKPiA+ICAJ CQlyZXR1cm4gTlVMTDsKPiA+ICAJCWlmIChkcm1fYXRvbWljX3N0YXRlX2luaXQoZGV2LCBzdGF0 ZSkgPCAwKSB7Cj4gCj4gLS0gCj4gSmFuaSBOaWt1bGEsIEludGVsIE9wZW4gU291cmNlIFRlY2hu b2xvZ3kgQ2VudGVyCgotLS0KVGhpcyBlbWFpbCBoYXMgYmVlbiBjaGVja2VkIGZvciB2aXJ1c2Vz IGJ5IEF2YXN0IGFudGl2aXJ1cyBzb2Z0d2FyZS4KaHR0cHM6Ly93d3cuYXZhc3QuY29tL2FudGl2 aXJ1cwoKX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KZHJp LWRldmVsIG1haWxpbmcgbGlzdApkcmktZGV2ZWxAbGlzdHMuZnJlZWRlc2t0b3Aub3JnCmh0dHBz Oi8vbGlzdHMuZnJlZWRlc2t0b3Aub3JnL21haWxtYW4vbGlzdGluZm8vZHJpLWRldmVsCg== From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752498AbdFOOYk (ORCPT ); Thu, 15 Jun 2017 10:24:40 -0400 Received: from mail-lf0-f65.google.com ([209.85.215.65]:34898 "EHLO mail-lf0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752441AbdFOOYi (ORCPT ); Thu, 15 Jun 2017 10:24:38 -0400 Date: Thu, 15 Jun 2017 16:24:30 +0200 From: Dawid Kurek To: Jani Nikula Cc: Daniel Vetter , Sean Paul , David Airlie , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] drm: Reduce scope of 'state' variable Message-ID: <20170615142430.GA13398@gmail.com> References: <20170615104142.GA29276@gmail.com> <871sqlzewc.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <871sqlzewc.fsf@intel.com> User-Agent: Mutt/1.7.1 (2016-10-04) X-Antivirus: Avast (VPS 170615-0, 15/06/2017), Outbound message X-Antivirus-Status: Clean Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 15/06/17, Jani Nikula wrote: > On Thu, 15 Jun 2017, Dawid Kurek wrote: > > Smaller scope reduces visibility of variable and makes usage of > > uninitialized variable less possible. > > --- > > drivers/gpu/drm/drm_atomic.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c > > index f32506a..ea5a9a7 100644 > > --- a/drivers/gpu/drm/drm_atomic.c > > +++ b/drivers/gpu/drm/drm_atomic.c > > @@ -108,10 +108,11 @@ struct drm_atomic_state * > > drm_atomic_state_alloc(struct drm_device *dev) > > { > > struct drm_mode_config *config = &dev->mode_config; > > - struct drm_atomic_state *state; > > > > if (!config->funcs->atomic_state_alloc) { > > - state = kzalloc(sizeof(*state), GFP_KERNEL); > > + struct drm_atomic_state *state > > + = kzalloc(sizeof(*state), GFP_KERNEL); > > Separate declaration and initialization would lead to a cleaner patch > and result. I saw combining declaration and initialization is quite common, i.e. in drm_atomic file. Personally, I also prefer those in one statement. But yes, it looks cleaner here, in two lines. v2 sent :) Thanks, Dawid > > BR, > Jani. > > > + > > if (!state) > > return NULL; > > if (drm_atomic_state_init(dev, state) < 0) { > > -- > Jani Nikula, Intel Open Source Technology Center --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus