From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752187AbcIOOx4 (ORCPT ); Thu, 15 Sep 2016 10:53:56 -0400 Received: from mailout4.w1.samsung.com ([210.118.77.14]:19436 "EHLO mailout4.w1.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751021AbcIOOxr (ORCPT ); Thu, 15 Sep 2016 10:53:47 -0400 X-AuditID: cbfec7f2-f79556d000002c42-1a-57dab5f7894f Subject: Re: [PATCH] leds: Introduce userspace leds driver To: Pavel Machek Cc: David Lechner , Richard Purdie , linux-kernel@vger.kernel.org, linux-leds@vger.kernel.org, Marcel Holtmann From: Jacek Anaszewski Message-id: Date: Thu, 15 Sep 2016 16:53:39 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-version: 1.0 In-reply-to: <20160915124103.GF13132@amd> Content-type: text/plain; charset=windows-1252; format=flowed Content-transfer-encoding: 7bit X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFupmleLIzCtJLcpLzFFi42LZduzned3vW2+FG7zsFLJY1CBmcXnXHDaL rW/WMVp8+/SL0eLuqaNsFrt3PWV1YPNYv3s5u8en/pOsHnvm/2D1WLH6O7vH501yAaxRXDYp qTmZZalF+nYJXBkH3qxjLbjFXbH98lOWBsaZnF2MnBwSAiYSHyduZ4OwxSQu3FsPZHNxCAks ZZRofDSNEcL5zCix98R2VriOP9OgqpYxSpzatoMFwnnGKPH1507mLkYODmEBK4meddwgDSIC 8hJb+1Ywg9QwC2xklLhyehkzSIJNwFDi54vXTCA2r4CdxIb5l1hBelkEVCUmNhmDmKICERK7 76ZCVAhK/Jh8jwXE5hTQlFjwcjXYFGYBR4kHi3ayQtjyEpvXvAVbJSGwiF3i/7o2sJESArIS mw4wQ9zvItH56R/Ux8ISr45vYYewZSQuT+5mgeidzChx8dhNVghnNaPExs5OFogqa4mG/79Y ILbxSUzaNp0ZYgGvREebEESJh8ST4x+gljlKHOp5xw4JnzeMErt+3mGawCg/C8lDs5A8MQvJ EwsYmVcxiqSWFuempxYb6xUn5haX5qXrJefnbmIEJpHT/45/2sH49YTVIUYBDkYlHt4Vc2+F C7EmlhVX5h5ilOBgVhLh3bYFKMSbklhZlVqUH19UmpNafIhRmoNFSZx3z4Ir4UIC6Yklqdmp qQWpRTBZJg5OqQbGsw7z/rUVx332XTy7sU1psd37I1cCMngez935rGDXManVjPWN148/tQ9L 017TFjTXYkPzSQlHVfU488uHjvmvcpY6x88/XdPo4pzo55kK32MNjJg//DC40Xs39rX+IYld rgYn5xRdk260vJN9/ebvuEsX9BdFuH+L3jFn6Yuv6/lsnYJW5UrkKbEUZyQaajEXFScCAEcK AIIeAwAA X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFlrJIsWRmVeSWpSXmKPExsVy+t/xa7rHt94KN5i6gsViUYOYxeVdc9gs tr5Zx2jx7dMvRou7p46yWeze9ZTVgc1j/e7l7B6f+k+yeuyZ/4PVY8Xq7+wenzfJBbBGudlk pCampBYppOYl56dk5qXbKoWGuOlaKCnkJeam2ipF6PqGBCkplCXmlAJ5RgZowME5wD1YSd8u wS3jwJt1rAW3uCu2X37K0sA4k7OLkZNDQsBE4uOfaWwQtpjEhXvrgWwuDiGBJYwSKx5/ZgRJ CAk8Y5TY8Seji5GDQ1jASqJnHTdIWERAXmJr3wpmiJI3jBJPF7qB9DILbGSU+Ny3HizBJmAo 8fPFayYQm1fATmLD/EusIHNYBFQlJjYZg4RFBSIkbq36yAhRIijxY/I9FhCbU0BTYsHL1WBj mAVsJRa8X8cCYctLbF7zlnkCo8AsJC2zkJTNQlK2gJF5FaNIamlxbnpusZFecWJucWleul5y fu4mRmA0bTv2c8sOxq53wYcYBTgYlXh4V8y9FS7EmlhWXJl7iFGCg1lJhHfbFqAQb0piZVVq UX58UWlOavEhRlOgHyYyS4km5wMjPa8k3tDE0NzS0MjYwsLcyEhJnHfqhyvhQgLpiSWp2amp BalFMH1MHJxSDYznBabLv2DaHO5+x6enU883k9PpvpCvkLnilzhtbpUAjr6XH2eFMGa+EBQ8 3arX9OLC3AV8hrxBIqXfd/9bXfpIal7nqnP3Dh99sEhwKefMZr/0TXZv39cZP+ph2Dh/guQU 54uhtid439h63sxXunYzec/UT0/1nx/jnaww5Vrjp4shv/YlL7ytxFKckWioxVxUnAgAZyY9 lbwCAAA= X-MTR: 20000000000000000@CPGS X-CMS-MailID: 20160915145342eucas1p1d975b82d7af67339e5d7e99a1bbc1376 X-Msg-Generator: CA X-Sender-IP: 182.198.249.180 X-Local-Sender: =?UTF-8?B?SmFjZWsgQW5hc3pld3NraRtTUlBPTC1TeXN0ZW0gRlcgIChN?= =?UTF-8?B?Qikb7IK87ISx7KCE7J6QG1NlbmlvciBTb2Z0d2FyZSBFbmdpbmVlcg==?= X-Global-Sender: =?UTF-8?B?SmFjZWsgQW5hc3pld3NraRtTUlBPTC1TeXN0ZW0gRlcgIChN?= =?UTF-8?B?QikbU2Ftc3VuZyBFbGVjdHJvbmljcxtTZW5pb3IgU29mdHdhcmUgRW5naW5l?= =?UTF-8?B?ZXI=?= X-Sender-Code: =?UTF-8?B?QzEwG0VIURtDMTBDRDAyQ0QwMjc1MjY=?= CMS-TYPE: 201P X-HopCount: 7 X-CMS-RootMailID: 20160915124112eucas1p1fe56716646346b23dc9ab06d92d7b5e0 X-RootMTR: 20160915124112eucas1p1fe56716646346b23dc9ab06d92d7b5e0 References: <1473128158-26915-1-git-send-email-david@lechnology.com> <04c5ee0d-9bfb-6e0a-2616-6cf720fc8763@samsung.com> <20160915124103.GF13132@amd> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Pavel, On 09/15/2016 02:41 PM, Pavel Machek wrote: > Hi! > >> Thanks for the patch. It is very nice. I have only one minor remark >> in the code. >> >> I think that it would be good to add a documentation for this >> driver to Documentation/leds, with exemplary C program instead >> of python one. The program could poll the dev node in a loop, >> which allows to conveniently check the impact of setting particular >> triggers and all other brightness change events. > > Actually, I'd say that python is fine -- it is used heavily in tools/. > > But perhaps the example program should go to tools/? I see python scripts only in perf tools. Let's stay by C application. David, could you please prepare another version of the patch, that splits test app code to the separate file in tools/leds (the directory doesn't exist so far), also providing suitable Makefile? >>> def change_brightness(b): >>> with open('/sys/class/leds/{}/brightness'.format(name) , 'w') as f: >>> f.write(str(b)) >>> >>> >>> with open('/dev/uleds', 'rb+', 0) as uleds: >>> bname = name.encode("ascii") >>> # create the leds class device >>> uleds.write(bname + b'\0' * (ULEDS_MAX_NAME_SIZE - len(bname))) > > Umm. I don't see it in the kernel code. You let userspace provide a > LED name? > > Where is the LED name tested for sanity? I guess there could be a lot > of fun naming a led ".." for example... Good point. -- Best regards, Jacek Anaszewski