From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Fri, 13 Sep 2013 08:25:42 +0200 (CEST) Received: from multi.imgtec.com ([194.200.65.239]:17445 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6816671Ab3IMGZj63Csy (ORCPT ); Fri, 13 Sep 2013 08:25:39 +0200 Message-ID: <523206B9.6000201@imgtec.com> Date: Thu, 12 Sep 2013 11:23:53 -0700 From: Leonid Yegoshin User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130106 Thunderbird/17.0.2 MIME-Version: 1.0 To: Lars-Peter Clausen CC: "Steven J. Hill" , , Subject: Re: [PATCH v2] MIPS: GIC: Select R4K counter as fallback. References: <1378929101-7021-1-git-send-email-Steven.Hill@imgtec.com> <52316D28.5000100@metafoo.de> In-Reply-To: <52316D28.5000100@metafoo.de> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.65.146] X-SEF-Processed: 7_3_0_01192__2013_09_13_07_24_34 Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 37811 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: Leonid.Yegoshin@imgtec.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips On 09/12/2013 12:28 AM, Lars-Peter Clausen wrote: > On 09/11/2013 09:51 PM, Steven J. Hill wrote: >> From: Leonid Yegoshin >> >> If CONFIG_CSRC_GIC is selected and the GIC is not found during >> boot, then fallback to the R4K counter gracefully. > Is there any reason not to always register the r4k clocksource, no matter > whether the gic clocksource is present or not? The timekeeping core of the > kernel will make sure to use the best available clocksource based on the > clocksource's rating. > > - Lars If you do power saving by switching some core OFF then you should do an additional clock sync after core revival. GIC is free from that but R4K is not. It was a primary reason for GIC clocksource. - Leonid. From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from multi.imgtec.com ([194.200.65.239]:17445 "EHLO multi.imgtec.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S6816671Ab3IMGZj63Csy (ORCPT ); Fri, 13 Sep 2013 08:25:39 +0200 Message-ID: <523206B9.6000201@imgtec.com> Date: Thu, 12 Sep 2013 11:23:53 -0700 From: Leonid Yegoshin MIME-Version: 1.0 Subject: Re: [PATCH v2] MIPS: GIC: Select R4K counter as fallback. References: <1378929101-7021-1-git-send-email-Steven.Hill@imgtec.com> <52316D28.5000100@metafoo.de> In-Reply-To: <52316D28.5000100@metafoo.de> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-Path: Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-subscribe: List-owner: List-post: List-archive: To: Lars-Peter Clausen Cc: "Steven J. Hill" , linux-mips@linux-mips.org, ralf@linux-mips.org Message-ID: <20130912182353.pH7pxSclRkobZjyT0gv9S06xnmNJ1xE89yfHpDWvISk@z> On 09/12/2013 12:28 AM, Lars-Peter Clausen wrote: > On 09/11/2013 09:51 PM, Steven J. Hill wrote: >> From: Leonid Yegoshin >> >> If CONFIG_CSRC_GIC is selected and the GIC is not found during >> boot, then fallback to the R4K counter gracefully. > Is there any reason not to always register the r4k clocksource, no matter > whether the gic clocksource is present or not? The timekeeping core of the > kernel will make sure to use the best available clocksource based on the > clocksource's rating. > > - Lars If you do power saving by switching some core OFF then you should do an additional clock sync after core revival. GIC is free from that but R4K is not. It was a primary reason for GIC clocksource. - Leonid.