From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lan Tianyu Subject: Re: [PATCH] ACPI/NVS: Not save NVS region for new machines to accelerate S3 Date: Mon, 21 Jul 2014 15:37:26 +0800 Message-ID: <53CCC336.4040302@intel.com> References: <1405662922-23606-1-git-send-email-tianyu.lan@intel.com> <20140718080056.GA2037@gchen.bj.intel.com> <53CC7787.2070302@intel.com> <20140721050105.GA21503@gchen.bj.intel.com> <53CCAB30.405@intel.com> <20140721062556.GA23297@gchen.bj.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Received: from mga03.intel.com ([143.182.124.21]:7282 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751476AbaGUHj5 (ORCPT ); Mon, 21 Jul 2014 03:39:57 -0400 In-Reply-To: <20140721062556.GA23297@gchen.bj.intel.com> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: rjw@rjwysocki.net, lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, gong.chen@linux.intel.com On 2014=E5=B9=B407=E6=9C=8821=E6=97=A5 14:25, Chen, Gong wrote: > On Mon, Jul 21, 2014 at 01:54:56PM +0800, Lan Tianyu wrote: >> Date: Mon, 21 Jul 2014 13:54:56 +0800 >> From: Lan Tianyu >> To: rjw@rjwysocki.net, lenb@kernel.org, linux-acpi@vger.kernel.org, >> linux-kernel@vger.kernel.org, gong.chen@linux.intel.com >> Subject: Re: [PATCH] ACPI/NVS: Not save NVS region for new machines = to >> accelerate S3 >> User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:14.0) Gecko/2= 0120714 >> Thunderbird/14.0 >> >> On 2014=E5=B9=B407=E6=9C=8821=E6=97=A5 13:01, Chen, Gong wrote: >>> On Mon, Jul 21, 2014 at 10:14:31AM +0800, Lan Tianyu wrote: >>>> Date: Mon, 21 Jul 2014 10:14:31 +0800 >>>> From: Lan Tianyu >>>> To: rjw@rjwysocki.net, lenb@kernel.org, linux-acpi@vger.kernel.org= , >>>> linux-kernel@vger.kernel.org, gong.chen@linux.intel.com >>>> Subject: Re: [PATCH] ACPI/NVS: Not save NVS region for new machine= s to >>>> accelerate S3 >>>> User-Agent: Mozilla/5.0 (X11; Linux i686 on x86_64; rv:14.0) Gecko= /20120714 >>>> Thunderbird/14.0 >>>> >>>> On 2014=E5=B9=B407=E6=9C=8818=E6=97=A5 16:00, Chen, Gong wrote: >>>>> On Fri, Jul 18, 2014 at 01:55:22PM +0800, Lan Tianyu wrote: >>>>>> Date: Fri, 18 Jul 2014 13:55:22 +0800 >>>>>> From: Lan Tianyu >>>>>> To: rjw@rjwysocki.net, lenb@kernel.org >>>>>> Cc: Lan Tianyu , linux-acpi@vger.kernel.or= g, >>>>>> linux-kernel@vger.kernel.org >>>>>> Subject: [PATCH] ACPI/NVS: Not save NVS region for new machines = to >>>>>> accelerate S3 >>>>>> X-Mailer: git-send-email 1.7.9.5 >>>>>> >>>>>> NVS region is saved and restored unconditionally for machines wi= thout >>>>>> nvs_nosave quirk during S3. Tested some new machines and the ope= ration >>>>>> is not necessary. Saving NVS region also affects S2RAM speed. Th= e time of >>>>>> NVS saving and restoring depends on the size of NVS region and i= t consumes >>>>>> 7~10ms normally. >>>>>> >>>>>> This patch is to make machines produced from 2012 to now not sav= ing NVS region >>>>>> to accelerate S3. >>>>>> >>>>> The year 2012 is a mandatory value in the spec? >>>>> >>>> >>>> No, spec indicates that this is only required for S4 and commit 2a= 6b697 >>>> added this behavior because this can fix S3 bug on some machines. = But >>>> this isn't necessary for all machines and waster time for S3. So t= his >>>> patch is to add time base quirk to change default behavior for new= machines. >>>> >>> If so, I don't think a hard-coded valud in the kernel is a good ide= a. >>> Why not providing a quirk via a command line parameter or module pa= rameter. >>> >> >> There is already a kernel command "acpi_sleep=3Dnonvs_s3" to do that= =2E But >> this needs to be set by user. Otherwise, saving/restoring NVS region >> also breaks system suspend on some machines and we have added 14 >> nonvs quirks in the acpisleep_dmi_table. >> > 14 quriks! What a terrible BIOS, isn't it? It's time to cleanup so > many hacks. If change the default behavior for old machines, that may cause some regressions and need to add new quirks to save/restore nvs region again= =2E > I'm not ACPI expert, but such yet another hack is not > acceptable from my point of view. >=20 --=20 Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" i= n the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html