From mboxrd@z Thu Jan 1 00:00:00 1970 From: Santosh Shilimkar Subject: Re: [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off Date: Wed, 13 Feb 2013 10:35:15 +0530 Message-ID: <511B1F0B.3020909@ti.com> References: <1360336306-18277-1-git-send-email-santosh.shilimkar@ti.com> <1360336306-18277-3-git-send-email-santosh.shilimkar@ti.com> <87d2wazep6.fsf@linaro.org> <5119CB2D.9040001@ti.com> <87bobpwog9.fsf@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from comal.ext.ti.com ([198.47.26.152]:41182 "EHLO comal.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750776Ab3BMFEB (ORCPT ); Wed, 13 Feb 2013 00:04:01 -0500 In-Reply-To: <87bobpwog9.fsf@linaro.org> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Kevin Hilman Cc: linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org On Tuesday 12 February 2013 08:48 PM, Kevin Hilman wrote: > Santosh Shilimkar writes: > >> On Saturday 09 February 2013 02:49 AM, Kevin Hilman wrote: >>> Santosh Shilimkar writes: >>> >>>> Current CPU PM code code make use of common cpu_suspend() path for all the >>>> CPU power states which is not optimal. In fact cpu_suspend() path is needed >>>> only when we put CPU power domain to off state where the CPU context is lost. >>>> >>>> Update the code accordingly so that the expensive cpu_suspend() path >>>> can be avoided for the shallow CPU power states like CPU PD INA/CSWR. >>>> >>>> Cc: Kevin Hilman >>>> >>>> Reported-by: Richard Woodruff >>>> Signed-off-by: Santosh Shilimkar >>> >>> Looks OK at first glance, but are you sure this is right for the >>> various ways both clusters might idle using coupled CPUidle? >>> >> Yes it is perfectly safe from all C-states. This patch has been part of >> the OMAP4/OMAP5 product port for some time. I forgot to send it upstream >> some how :( >> >>> Some description of the testing would be helpful here. >>> >> Sorry. Should have mentioned it in first place. >> Patch is being tested on OMAP4430 (idle/suspend) and OMAP5 with >> few out of tree patches. > > OK, please update changelog with a brief description of how it was > tested, and on which platforms. > Will update the changelog and post it Regards, Santosh From mboxrd@z Thu Jan 1 00:00:00 1970 From: santosh.shilimkar@ti.com (Santosh Shilimkar) Date: Wed, 13 Feb 2013 10:35:15 +0530 Subject: [PATCH] ARM: OMAP4: PM: Avoid expensive cpu_suspend() path for all CPU power states except off In-Reply-To: <87bobpwog9.fsf@linaro.org> References: <1360336306-18277-1-git-send-email-santosh.shilimkar@ti.com> <1360336306-18277-3-git-send-email-santosh.shilimkar@ti.com> <87d2wazep6.fsf@linaro.org> <5119CB2D.9040001@ti.com> <87bobpwog9.fsf@linaro.org> Message-ID: <511B1F0B.3020909@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Tuesday 12 February 2013 08:48 PM, Kevin Hilman wrote: > Santosh Shilimkar writes: > >> On Saturday 09 February 2013 02:49 AM, Kevin Hilman wrote: >>> Santosh Shilimkar writes: >>> >>>> Current CPU PM code code make use of common cpu_suspend() path for all the >>>> CPU power states which is not optimal. In fact cpu_suspend() path is needed >>>> only when we put CPU power domain to off state where the CPU context is lost. >>>> >>>> Update the code accordingly so that the expensive cpu_suspend() path >>>> can be avoided for the shallow CPU power states like CPU PD INA/CSWR. >>>> >>>> Cc: Kevin Hilman >>>> >>>> Reported-by: Richard Woodruff >>>> Signed-off-by: Santosh Shilimkar >>> >>> Looks OK at first glance, but are you sure this is right for the >>> various ways both clusters might idle using coupled CPUidle? >>> >> Yes it is perfectly safe from all C-states. This patch has been part of >> the OMAP4/OMAP5 product port for some time. I forgot to send it upstream >> some how :( >> >>> Some description of the testing would be helpful here. >>> >> Sorry. Should have mentioned it in first place. >> Patch is being tested on OMAP4430 (idle/suspend) and OMAP5 with >> few out of tree patches. > > OK, please update changelog with a brief description of how it was > tested, and on which platforms. > Will update the changelog and post it Regards, Santosh