From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nishanth Menon Subject: Re: [PATCH V3 0/6] cpufreq: suspend early/resume late Date: Mon, 25 Nov 2013 15:37:43 -0600 Message-ID: <5293C327.2030606@ti.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: cpufreq-owner@vger.kernel.org To: Viresh Kumar , rjw@rjwysocki.net Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, cpufreq@vger.kernel.org, linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org, swarren@wwwdotorg.org, kgene.kim@samsung.com, linux-samsung-soc@vger.kernel.org, linux-tegra@vger.kernel.org, jinchoi@broadcom.com, tianyu.lan@intel.com, sebastian.capella@linaro.org, jhbird.choi@samsung.com List-Id: linux-tegra@vger.kernel.org On 11/25/2013 08:11 AM, Viresh Kumar wrote: > This patchset adds cpufreq callbacks to dpm_{suspend|resume}() for handling > suspend/resume of cpufreq governors and core. This is required for early suspend > and late resume of governors and cpufreq core. > > There are multiple problems that are fixed by this patch: > - Nishanth Menon (TI) found an interesting problem on his platform, OMAP. His board > wasn't working well with suspend/resume as calls for removing non-boot CPUs > was turning out into a call to drivers ->target() which then tries to play > with regulators. But regulators and their I2C bus were already suspended and > this resulted in a failure. Many platforms have such problems, samsung, tegra, > etc.. They solved it with driver specific PM notifiers where they used to > disable their driver's ->target() routine. Most of these are updated in this > patchset to use new infrastructure. > > - Lan Tianyu (Intel) & Jinhyuk Choi (Broadcom) found another issue where > tunables configuration for clusters/sockets with non-boot CPUs was getting > lost after suspend/resume, as we were notifying governors with > CPUFREQ_GOV_POLICY_EXIT on removal of the last cpu for that policy and so > deallocating memory for tunables. This is also fixed with this patch as don't > allow any operation on Governors during suspend/resume now. > > > So to solve these issues we introduce early suspend and late resume callbacks > which would remove need of cpufreq drivers to implement PM notifiers to disable > transition after suspend and before resume. > > @Nishanth: Can you please test V2 as well and confirm that suspend_noirq() > doesn't work for you. I am sure it will not, but would be better if you confirm > that. > > Viresh Kumar (6): > cpufreq: suspend governors on system suspend/hibernate > cpufreq: call driver's suspend/resume for each policy patches 1-2, Tested-by: Nishanth Menon http://pastebin.mozilla.org/3670932 Prior to these two patches: http://pastebin.mozilla.org/3670933 cpufreq driver used: cpufreq_cpu0 -- Regards, Nishanth Menon