From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: [PATCH v4 7/8] qcom: cpuidle: Add cpuidle driver for QCOM cpus Date: Wed, 27 Aug 2014 10:31:26 -0700 Message-ID: <7hvbpdet5d.fsf@paris.lan> References: <1408486537-6358-1-git-send-email-lina.iyer@linaro.org> <1408486537-6358-8-git-send-email-lina.iyer@linaro.org> <53F54A5C.3060002@linaro.org> <20140821143643.GA60920@ilina-mac.local> Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from mail-pa0-f46.google.com ([209.85.220.46]:34957 "EHLO mail-pa0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933914AbaH0Rbe (ORCPT ); Wed, 27 Aug 2014 13:31:34 -0400 Received: by mail-pa0-f46.google.com with SMTP id lj1so695305pab.19 for ; Wed, 27 Aug 2014 10:31:31 -0700 (PDT) In-Reply-To: <20140821143643.GA60920@ilina-mac.local> (Lina Iyer's message of "Thu, 21 Aug 2014 08:36:43 -0600") Sender: linux-arm-msm-owner@vger.kernel.org List-Id: linux-arm-msm@vger.kernel.org To: Lina Iyer Cc: Daniel Lezcano , sboyd@codeaurora.org, davidb@codeaurora.org, galak@codeaurora.org, linux-arm-msm@vger.kernel.org, lorenzo.pieralisi@arm.com, msivasub@codeaurora.org Lina Iyer writes: > On Thu, Aug 21, 2014 at 03:24:44AM +0200, Daniel Lezcano wrote: >>On 08/20/2014 12:15 AM, Lina Iyer wrote: [...] >> >> So IIUC, if you specify the index 1, that means the state[0] will be >> the default WFI. But you override the callback below in the loop. >> >> I recommend you use the default arm wfi callback but you implement >> the cpu_do_idle for your platform. > > Yes, it was intended. I dont want to define two WFI states. The > architectural WFI does not buy us enough compared to WFI that SoC can > do. L2 can go into low power modes when the core is in WFI and for that > I would like to have all WFI's enter SoC framework. If the L2 is going into low-power, that means there will be higher latency coming out compared to the architectural WFI, correct? If you have both, and the latency/residency numbers are accurate, the governor is then left to pick the right one. So, what's wrong with having both? Kevin