From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Rafael J. Wysocki" Subject: Re: [PATCH v4 2/5] ACPI / processor_idle: Add support for Low Power Idle(LPI) states Date: Tue, 10 May 2016 02:04:41 +0200 Message-ID: <3339348.mi5ytyqrb0@vostro.rjw.lan> References: <1461069013-13292-1-git-send-email-sudeep.holla@arm.com> <1461069013-13292-3-git-send-email-sudeep.holla@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <1461069013-13292-3-git-send-email-sudeep.holla@arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Sudeep Holla Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Lorenzo Pieralisi , Al Stone , Prashanth Prakash , Ashwin Chaugule List-Id: linux-acpi@vger.kernel.org On Tuesday, April 19, 2016 01:30:10 PM Sudeep Holla wrote: > ACPI 6.0 introduced an optional object _LPI that provides an alternate > method to describe Low Power Idle states. It defines the local power > states for each node in a hierarchical processor topology. The OSPM can > use _LPI object to select a local power state for each level of processor > hierarchy in the system. They used to produce a composite power state > request that is presented to the platform by the OSPM. > > Since multiple processors affect the idle state for any non-leaf hierarchy > node, coordination of idle state requests between the processors is > required. ACPI supports two different coordination schemes: Platform > coordinated and OS initiated. > > This patch adds initial support for Platform coordination scheme of LPI. > > Cc: "Rafael J. Wysocki" > Signed-off-by: Sudeep Holla > --- > drivers/acpi/bus.c | 11 +- > drivers/acpi/processor_driver.c | 2 +- > drivers/acpi/processor_idle.c | 441 +++++++++++++++++++++++++++++++++++----- > include/acpi/processor.h | 25 ++- > include/linux/acpi.h | 4 + > 5 files changed, 422 insertions(+), 61 deletions(-) > > Hi Rafael, > > Yet to be discussed(retained as in from previous version): I somehow didn't realize that you had been waiting for my feedback. Sorry about that. > - Kconfig entry removal: Need feedback on how to deal with that > without having to introduce dummy _CST related ARM64 callbacks > - Didn't defer processing of LPI buffers to flattening as it > results in the same buffer decoded multiple times > - ACPI_CSTATE_INTEGER : IMO it's reasonable to keep it aroundsince the > it's part of LPI specification(not just ARM FFH) OK, I'll have a look tomorrow. Thanks, Rafael