From mboxrd@z Thu Jan 1 00:00:00 1970 From: Arnd Bergmann Subject: Re: [PATCH 18/20] clocksource / acpi: Add macro CLOCKSOURCE_ACPI_DECLARE Date: Wed, 22 Jan 2014 15:56:05 +0100 Message-ID: <3140612.0s75qS6VKb@wuerfel> References: <1389961514-13562-1-git-send-email-hanjun.guo@linaro.org> <52DCE790.6080809@linaro.org> <20140122114616.GB15591@e106331-lin.cambridge.arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Return-path: In-Reply-To: <20140122114616.GB15591@e106331-lin.cambridge.arm.com> Sender: linux-kernel-owner@vger.kernel.org To: Mark Rutland Cc: Hanjun Guo , "Rafael J. Wysocki" , Catalin Marinas , Will Deacon , Russell King - ARM Linux , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "grant.likely@linaro.org" , Matthew Garrett , Olof Johansson , Linus Walleij , Bjorn Helgaas , Rob Herring , "patches@linaro.org" , "linux-kernel@vger.kernel.org" , "linaro-kernel@lists.linaro.org" , "linaro-acpi@lists.linaro.org" , Charles Garcia-Tobin , Amit List-Id: linux-acpi@vger.kernel.org On Wednesday 22 January 2014 11:46:16 Mark Rutland wrote: > On Mon, Jan 20, 2014 at 09:08:32AM +0000, Hanjun Guo wrote: > > On 2014-1-17 22:21, Arnd Bergmann wrote: > > > On Friday 17 January 2014, Hanjun Guo wrote: > > >> > > >> From: Amit Daniel Kachhap > > >> > > >> This macro does the same job as CLOCKSOURCE_OF_DECLARE. The device > > >> name from the ACPI timer table is matched with all the registered > > >> timer controllers and matching initialisation routine is invoked. > > > > > > I wouldn't anticipate this infrastructure to be required. Shouldn't all > > > ARMv8 machines have an architected timer? > > > > I not sure of this, could anyone can give some guidance? if only arch > > timer is available for ARM64, this will make thing very simple. > > All ARMv8 systems should have an architected timer. > > However, they may also have other timers (e.g. global timers for use > when CPUs are in low power states and their local architected timers > aren't active). But all other timers could be regular platform drivers I suppose. No need for special infrastructure for those. Arnd