On 2014年07月21日 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 <tianyu....@intel.com> >> To: r...@rjwysocki.net, l...@kernel.org, linux-a...@vger.kernel.org, >> linux-kernel@vger.kernel.org, gong.c...@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/20120714 >> Thunderbird/14.0 >> >> On 2014年07月21日 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 <tianyu....@intel.com> >>>> To: r...@rjwysocki.net, l...@kernel.org, linux-a...@vger.kernel.org, >>>> linux-kernel@vger.kernel.org, gong.c...@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/20120714 >>>> Thunderbird/14.0 >>>> >>>> On 2014年07月18日 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 <tianyu....@intel.com> >>>>>> To: r...@rjwysocki.net, l...@kernel.org >>>>>> Cc: Lan Tianyu <tianyu....@intel.com>, linux-a...@vger.kernel.org, >>>>>> 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 without >>>>>> nvs_nosave quirk during S3. Tested some new machines and the operation >>>>>> is not necessary. Saving NVS region also affects S2RAM speed. The time of >>>>>> NVS saving and restoring depends on the size of NVS region and it >>>>>> consumes >>>>>> 7~10ms normally. >>>>>> >>>>>> This patch is to make machines produced from 2012 to now not saving 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 2a6b697 >>>> 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 this >>>> 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 idea. >>> Why not providing a quirk via a command line parameter or module parameter. >>> >> >> There is already a kernel command "acpi_sleep=nonvs_s3" to do that. 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. > I'm not ACPI expert, but such yet another hack is not > acceptable from my point of view. > -- Best regards Tianyu Lan -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
