From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AB8JxZrSutIzeIJd1iX7gXgCKiuPEL9qm4WSCNu1nAL2w0+8Dw60dvz8K11OrMHzpW2YTbaN9882 ARC-Seal: i=1; a=rsa-sha256; t=1525807535; cv=none; d=google.com; s=arc-20160816; b=YfrCPAp/49mVn+nfzB/CkmfVoPY9vWm6J7oHkz4lX9ppRKqpULXgobi+O80EMp/5mW uT/hMbzrL5f5NFmAYzyVUvXftjNoG4LUCSdnPqrjhLOEULOO6Tjj9zeaaAtrX5JpFE3S r1Vi+AnOzwqKh6hFMyf8eBzRYde+CWwP/7AwtfLHWW2Qkrm7+naGTeUyjLE31tBMBY3+ XEsbfzbqzAh4fyo8FwgW8i+YOmP3CL/XlbGuJPiYt6kJgZIy5b8oKUllg1LNUBJBFSQf hjIgx1vqxX/mdZVAunFUqI/B+TP5HvFdFSwD4R4WL+eU+5P93OL+HAsXIwr6JsceR/Hv SRdQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature :arc-authentication-results; bh=Z5jTOfD0FfZw/KBahVDyYRy7Th0avOVtmAp5e1QnJz8=; b=0RhCboBvNO3wEQLJ0Q7ij6LOS7ikLVD7vGd6/BWRgo0U+XkoHKexCqkSckOZDLDmEK QTLjQkvFPhhgyFrOix8wW+G+OOZo3E8ZeG+Haf3sSSaxF1YGz/Bf4aN179sX8LiHrAvg IIyeWFZfiwtGETTcbbTp2JKw2F2ErQbKkvDwxvPzt0y3Zdtl8frtZOKkrdFXlYsC6wBy wpDpuiM8Z3Q++UkN3kQPhpbwcuEYVVcFUSyAqglHVN90CU2xLXpZ0PnJR6+8J9FV2JIy qof4yG0vMprN/fl6jb4gaq72dcgjybVoxiegIFMhsm9QZ48wvA6Nn5qj9qLphwVX9aNu 0VgA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Z+KOEbJE; spf=pass (google.com: domain of helgaas@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=helgaas@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Authentication-Results: mx.google.com; dkim=pass header.i=@kernel.org header.s=default header.b=Z+KOEbJE; spf=pass (google.com: domain of helgaas@kernel.org designates 198.145.29.99 as permitted sender) smtp.mailfrom=helgaas@kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=kernel.org Date: Tue, 8 May 2018 14:25:32 -0500 From: Bjorn Helgaas To: Keith Busch Cc: Sinan Kaya , Oza Pawandeep , Bjorn Helgaas , Philippe Ombredanne , Thomas Gleixner , Greg Kroah-Hartman , Kate Stewart , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dongdong Liu , Wei Zhang , Timur Tabi , Alex Williamson Subject: Re: [PATCH v12 0/6] Address error and recovery for AER and DPC Message-ID: <20180508192532.GA79697@bhelgaas-glaptop.roam.corp.google.com> References: <1519837457-3596-1-git-send-email-poza@codeaurora.org> <20180311220337.GA194000@bhelgaas-glaptop.roam.corp.google.com> <04ade52e-d1ea-fe67-bb26-246621d159e6@codeaurora.org> <20180312142551.GB18494@localhost.localdomain> <20180312194236.GA12195@bhelgaas-glaptop.roam.corp.google.com> <20180312232626.GI18494@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180312232626.GI18494@localhost.localdomain> User-Agent: Mutt/1.9.2 (2017-12-15) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1593665102741565714?= X-GMAIL-MSGID: =?utf-8?q?1599925162285092341?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Mon, Mar 12, 2018 at 05:26:26PM -0600, Keith Busch wrote: > On Mon, Mar 12, 2018 at 02:47:30PM -0500, Bjorn Helgaas wrote: > > On Mon, Mar 12, 2018 at 08:25:51AM -0600, Keith Busch wrote: > > > Per spec, DPC is the recommended way for handling surprise removal > > > events and even recommends DPC capable slots *not* set 'Surprise' > > > in Slot Capabilities so that removals are always handled by DPC. This > > > service driver was developed with that use in mind. > > > > Thanks for this tip. The only thing I've found so far is the mention > > of Surprise Down triggering DPC in the last paragraph of sec 6.7.5. > > Are there other references I should look at? I haven't found the > > recommendation about not setting 'Surprise' in Slot Capabilities yet. > > No problem, it's in the "IMPLEMENTATION NOTE" at the end of 6.2.10.4, > "Avoid Disabled Link and Hot-Plug Surprise Use with DPC". > > Outside the spec, Microsemi as one of the PCI-SIG contributors and early > adopters of the capability published a white paper "Hot and Surprise > Plug Recommendations for Enterprise PCIe" providing guidance for OS > drivers using DPC. We originally developed to that guidance. The paper > unfortunately appears to be pay-walled now. :( Any chance you have a URL or contact info for this pay-walled white paper? Sounds like it might have useful information in it.