From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752118AbeAXBf7 (ORCPT ); Tue, 23 Jan 2018 20:35:59 -0500 Received: from mail-pf0-f196.google.com ([209.85.192.196]:35512 "EHLO mail-pf0-f196.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751682AbeAXBfz (ORCPT ); Tue, 23 Jan 2018 20:35:55 -0500 X-Google-Smtp-Source: AH8x225B0DHSojHrebN2FS/Is3mUuT5PipeVsM44HEnT8xzvjlbK5bzBnueDbBR2XOLsggzejs/oww== Date: Wed, 24 Jan 2018 09:35:05 +0800 From: Peng Fan To: Peng Fan Cc: shawnguo@kernel.org, kernel@pengutronix.de, fabio.estevam@nxp.com, aisheng.dong@nxp.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/2] ARM: imx: cpuidle-imx6q: configure CCM to RUN mode when CPU is active Message-ID: <20180124013505.GB9401@shlinux2> References: <1514641999-20521-1-git-send-email-peng.fan@nxp.com> <1514641999-20521-2-git-send-email-peng.fan@nxp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1514641999-20521-2-git-send-email-peng.fan@nxp.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, For the two patch, ping.. On Sat, Dec 30, 2017 at 09:53:19PM +0800, Peng Fan wrote: >There are two states in i.MX6Q cpuidle driver. >state[1]: ARM WFI mode >state[2]: i.MX6Q WAIT mode > >Take i.MX6DL as example, think out such a case: >1. CPU0/1 both run at normal mode >2. On CPU0, `sleep 1` is executed. And there are no workload on CPU1. >3. CPU0 first runs into state[2] and 'wfi' instruction. Switched to use > GPT broadcast. >4. CPU1 runs into state[2] and configure CCM to WAIT MODE, > then 'wfi' instruction. Now arm_clk and local timer clock are > shutdown. Switched to use GPT broadcast >5. GPT broadcast timer interrupt comes to GPC/GIC, then CPU0 wakes up. > CPU0 switched to use arm local timer. CPU1 is still sleeping. >6. No workload on CPU0, CPU0 runs into state[1]. But CCM register > is still not restored to Normal RUN mode. 'wfi' + CCM WAIT will > cause arm_clk and arm core clk. > Now CPU0 stops, which is not correct. > >So, need to make sure CCM configured to RUN mode when any cpu exit >state[2]. > >In this patch, >When CPU exits state[2], it configures CCM to RUN mode. >When all CPUs enters state[2], the last CPU needs to check >whether it's ok to configure CCM to WAIT mode or not. > >Signed-off-by: Peng Fan >--- > >V1: > This is to upstream patch: > http://git.freescale.com/git/cgit.cgi/imx/linux-imx.git/commit/?h=imx_4.9.11_1.0.0_ga&id=0d980646ee068b92db71fd5e4e4efcbc33749cbd > > arch/arm/mach-imx/cpuidle-imx6q.c | 3 +++ > 1 file changed, 3 insertions(+) > >diff --git a/arch/arm/mach-imx/cpuidle-imx6q.c b/arch/arm/mach-imx/cpuidle-imx6q.c >index bfeb25aaf9a2..4d342e2fdfe6 100644 >--- a/arch/arm/mach-imx/cpuidle-imx6q.c >+++ b/arch/arm/mach-imx/cpuidle-imx6q.c >@@ -30,6 +30,8 @@ static int imx6q_enter_wait(struct cpuidle_device *dev, > if (!spin_trylock(&master_lock)) > goto idle; > imx6_set_lpm(WAIT_UNCLOCKED); >+ if (atomic_read(&master) != num_online_cpus()) >+ imx6_set_lpm(WAIT_CLOCKED); > cpu_do_idle(); > imx6_set_lpm(WAIT_CLOCKED); > spin_unlock(&master_lock); >@@ -41,6 +43,7 @@ static int imx6q_enter_wait(struct cpuidle_device *dev, > done: > atomic_dec(&master); > >+ imx6_set_lpm(WAIT_CLOCKED); > return index; > } > >-- >2.14.1 > Thanks, Peng. --