From mboxrd@z Thu Jan 1 00:00:00 1970 From: Grygorii Strashko Subject: Re: [PATCH RT 11/20] ARM: imx: always use TWD on IMX6Q Date: Mon, 18 Jul 2016 20:18:59 +0300 Message-ID: <578D0F83.2010403@ti.com> References: <20160712142405.634544943@goodmis.org> <20160712142419.367116752@goodmis.org> <20160712200429.GA4302@linutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: , linux-rt-users , Thomas Gleixner , Carsten Emde , John Kacur , Paul Gortmaker To: Sebastian Andrzej Siewior , Steven Rostedt Return-path: Received: from arroyo.ext.ti.com ([198.47.19.12]:47099 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751451AbcGRST0 (ORCPT ); Mon, 18 Jul 2016 14:19:26 -0400 In-Reply-To: <20160712200429.GA4302@linutronix.de> Sender: linux-rt-users-owner@vger.kernel.org List-ID: On 07/12/2016 11:04 PM, Sebastian Andrzej Siewior wrote: > * Steven Rostedt | 2016-07-12 10:24:16 [-0400]: > >> 4.1.27-rt31-rc1 stable review patch. >> If anyone has any objections, please let me know. > > I don't recommend to cherry-pick this. The symbol it selects > (HAVE_ARM_TWD) has "depends on SMP" in v4.1. In v4.4 there should be > AM43xx which is UP and also uses the TWD so the change is simple here. > yes. AM43xx is UP and supports ARM TWD, but there could be some 'issues' in !RT case :( ARM TWD might be powered off in deep CPU Idle states and lose its context if !RT & CPUIDLE, so there are should be backup broadcast timer configured. And that can cause build issues related to tick_broadcast()->smp_cross_call(). I've solved it locally for OMAP2 only: commit 0b3e6fca4d1af4aa150d32506220f4241323a00c ^Just FYI. But may be it can be done in more generic way. regards, -grygorii