From mboxrd@z Thu Jan 1 00:00:00 1970 From: Viresh Kumar Subject: Re: [PATCH 2/2] cpufreq: powernv: Use PMSR to verify global and local pstate Date: Fri, 4 Nov 2016 12:11:32 +0530 Message-ID: <20161104064132.GB3414@vireshk-i7> References: <1478237255-4258-1-git-send-email-akshay.adiga@linux.vnet.ibm.com> <1478237255-4258-2-git-send-email-akshay.adiga@linux.vnet.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mail-pf0-f173.google.com ([209.85.192.173]:36601 "EHLO mail-pf0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934004AbcKDGlg (ORCPT ); Fri, 4 Nov 2016 02:41:36 -0400 Received: by mail-pf0-f173.google.com with SMTP id 189so46231528pfz.3 for ; Thu, 03 Nov 2016 23:41:36 -0700 (PDT) Content-Disposition: inline In-Reply-To: <1478237255-4258-2-git-send-email-akshay.adiga@linux.vnet.ibm.com> Sender: linux-pm-owner@vger.kernel.org List-Id: linux-pm@vger.kernel.org To: Akshay Adiga Cc: rjw@rjwysocki.net, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org On 04-11-16, 10:57, Akshay Adiga wrote: > As fast_switch may get called in interrupt disable mode, it does not s/in interrupt disable mode/with interrupts disabled s/it does/it may > update the global_pstate_info data structure. Hence the global_pstate_info > has stale data whenever pstate is updated through fast_swtich(). s/has/may have s/swtich/switch > > So the gpstate_timer can fire after a fast_switch() call has update s/So the/The s/a fast_swtich() call has update/the fast_switch() call has updated > the pstates to a different value. Hence the timer handler cannot rely > on the cached values of local and global pstate and needs to read it > from the PMSR. > > Signed-off-by: Akshay Adiga > > --- > drivers/cpufreq/powernv-cpufreq.c | 32 ++++++++++++++++++++++---------- > 1 file changed, 22 insertions(+), 10 deletions(-) I am not the best guy to judge the code changes here. Can you please include Shilpa and Gautham to the mail chain and get there feedback. -- viresh