From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Kani, Toshi" Subject: Re: [PATCH 0/4] Adding support to parse BERT for libnvdimm Date: Fri, 30 Mar 2018 15:04:58 +0000 Message-ID: <1522422276.2693.268.camel@hpe.com> References: <152236282506.35558.2067249639136170490.stgit@djiang5-desk3.ch.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <152236282506.35558.2067249639136170490.stgit-Cxk7aZI4ujnJARH06PadV2t3HXsI98Cx0E9HWUfgJXw@public.gmane.org> Content-Language: en-US Content-ID: <611C14C1B0FB5C43A134DC8BADA16EC5-mmYPd6ayCNGroOM5E8FhRbjFIynDaujOfM0AETQt39g@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linux-nvdimm-bounces-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org Sender: "Linux-nvdimm" To: "dan.j.williams-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "dave.jiang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" Cc: "linux-nvdimm-hn68Rpc1hR1g9hUCZPvPmw@public.gmane.org" , "tony.luck-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "rjw-LthD3rsA81gm4RdzfppkhA@public.gmane.org" , "linux-acpi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "lenb-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org" List-Id: linux-acpi@vger.kernel.org On Thu, 2018-03-29 at 15:37 -0700, Dave Jiang wrote: > The following series implements support for parsing of the BERT records > and adding the error memory ranges to nvdimm badblocks in order for the > kernel to avoid prevent the kernel from accessing those areas. And with > the addition of this support, we can surface the nd regions instead of waiting > for ARS to complete. So the ARS handling is reworked to run in the > background and not block nd region registration. Hi Dave, I agree on the problem, and adding an ability to obtain pmem badblocks records at boot-time without waiting for a new ARS scan to complete is a good option for users. However, I do not think using the BERT table is a good approach. This requires FW to report pmem badblocks records with a new interface in addition to ARS records, which FW already implements for pmem. ACPI 6.2 defines Start ARS with Flags Bit[1] set to report badblocks record without starting a new ARS scan. We set this bit after receiving a 0x81 notification at this point. Can we use ARS with Flags bit[1] set at boot-time so that both OS and FW can use the same ARS implementation? Thanks, -Toshi