Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756822AbcLUVBX (ORCPT ); Wed, 21 Dec 2016 16:01:23 -0500 Received: from ec2-52-27-115-49.us-west-2.compute.amazonaws.com ([52.27.115.49]:33070 "EHLO osg.samsung.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752035AbcLUVBV (ORCPT ); Wed, 21 Dec 2016 16:01:21 -0500 Subject: Re: [PATCH] at86rf230: Allow slow GPIO pins for "rstn" To: Chris Healy References: <1482103533-13187-1-git-send-email-andrew.smirnov@gmail.com> <7435a0a2-3f0f-a0db-9e0e-cb1ac838737c@osg.samsung.com> Cc: Alexander Aring , Andrey Smirnov , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, linux-wpan@vger.kernel.org From: Stefan Schmidt Message-ID: Date: Wed, 21 Dec 2016 22:01:15 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1242 Lines: 44 Hello. On 21/12/16 19:30, Chris Healy wrote: > > > On Dec 21, 2016 5:11 AM, "Stefan Schmidt" > wrote: > > Hello. > > > On 19/12/16 00:25, Andrey Smirnov wrote: > > Driver code never touches "rstn" signal in atomic context, so > there's > no need to implicitly put such restriction on it by using > gpio_set_value > to manipulate it. Replace gpio_set_value to > gpio_set_value_cansleep to > fix that. > > > We need to make sure we are not assuming it can be called in such a > context in the future now. But that is something we can worry about > if it comes up. > > > As a an example of where such restriction might be inconvenient, > consider a hardware design where "rstn" is connected to a pin of > I2C/SPI > GPIO expander chip. > > > Is this a real life issue you run into? > > > I have a platform with this configuration. The DTS for the platform is > in the process of being mainlined right now. Thanks for letting us know. What platform is that? I'm always interested in hearing about devices that use the Linux ieee802154 subsystem. :) regards Stefan Schmidt