Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751621AbcDFQNZ (ORCPT ); Wed, 6 Apr 2016 12:13:25 -0400 Received: from mail-wm0-f50.google.com ([74.125.82.50]:34766 "EHLO mail-wm0-f50.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751085AbcDFQNX convert rfc822-to-8bit (ORCPT ); Wed, 6 Apr 2016 12:13:23 -0400 MIME-Version: 1.0 In-Reply-To: References: <1459801326-5541-1-git-send-email-ezequiel@vanguardiasur.com.ar> <1459801326-5541-5-git-send-email-ezequiel@vanguardiasur.com.ar> Date: Wed, 6 Apr 2016 13:13:21 -0300 Message-ID: Subject: Re: [PATCH 4/5] devicetree: leds: Introduce "panic-blink" optional property From: Ezequiel Garcia To: Rob Herring Cc: Linux LED Subsystem , "linux-kernel@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Richard Purdie , Jacek Anaszewski Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1537 Lines: 37 On 6 April 2016 at 12:12, Rob Herring wrote: > On Mon, Apr 4, 2016 at 3:22 PM, Ezequiel Garcia > wrote: >> It's desirable to specify which LEDs are to be blinked on a kernel >> panic. Therefore, introduce a devicetree boolean property to mark >> which LEDs should be treated this way. >> >> Signed-off-by: Ezequiel Garcia >> --- >> Documentation/devicetree/bindings/leds/common.txt | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/Documentation/devicetree/bindings/leds/common.txt b/Documentation/devicetree/bindings/leds/common.txt >> index 68419843e32f..dd409df9203a 100644 >> --- a/Documentation/devicetree/bindings/leds/common.txt >> +++ b/Documentation/devicetree/bindings/leds/common.txt >> @@ -37,6 +37,8 @@ Optional properties for child nodes: >> property is mandatory for the LEDs in the non-flash modes >> (e.g. torch or indicator). >> >> +- panic-blink : Mark this LED to be used by the panic LED trigger. >> + > > We already have a way to specify LED triggers. Why can't that be used? > Because this is not about specifying a LED trigger. The use case is the following: a LED is assigned to some LED trigger. When the kernel panics, we want to switch that LED to the panic trigger, so it blinks signalling the panic. IOW, this allows a LED to be used for "normal operation stuff trigger", but blink if the kernel panics. -- Ezequiel García, VanguardiaSur www.vanguardiasur.com.ar