From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthew Locke Subject: PowerOP vs OPpoint Date: Thu, 14 Sep 2006 02:22:25 -0700 Message-ID: Mime-Version: 1.0 (Apple Message framework v624) Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: linux-pm-bounces@lists.osdl.org Errors-To: linux-pm-bounces@lists.osdl.org To: pm list Cc: kernel list List-Id: linux-pm@vger.kernel.org Unfortunately, there are two efforts underway that makes this confusing = and I think require a bit more than the short summary requested. A one = paragraph summary can't address the why and how. This email briefly = describes the why and the differences. There are two main reasons for both these efforts: - existing power management interfaces do not enable the power = management features on the latest SOC's used in embedded mobile = devices - existing power management interfaces do not provide the API necessary = to build power managers (userspace and/or kernel space) that optimize = power consumption to level required by embedded mobile devices PowerOP Focus is on a platform independent interface for selecting and creating = operating points. We want to get the basic power management block in = place and build on it. Integrating with other existing power = management interfaces as it makes sense. The first natural integration = point is the cpufreq_driver layer in cpufreq and does not affect the = userspace interface. OPpoint Goal is to show how all existing interfaces can use the operating point = concept. It is more than an interface for selecting and creating = operating points. It integrates with cpufreq and sleep states defining = new userspace interfaces and using existing interfaces in different = ways. There are a lot of issues with the OPpoint operating point = interface that was discussed here: = http://lists.osdl.org/pipermail/linux-pm/2006-August/003541.html . = Many objections to the sleep state integration. Most of the negative = comments about cpufreq are about the OPpoint patches. I have not seen or heard any justification for the OPpoint patches to = create a different operating point interface. Matt