From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx1.redhat.com [209.132.183.28]) by dpdk.org (Postfix) with ESMTP id 8D19C1B2D1 for ; Thu, 12 Oct 2017 15:08:30 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 58C47723A6; Thu, 12 Oct 2017 13:08:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 58C47723A6 Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx09.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=aconole@redhat.com Received: from dhcp-25-97.bos.redhat.com (unknown [10.18.25.172]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 65C8217D35; Thu, 12 Oct 2017 13:08:28 +0000 (UTC) From: Aaron Conole To: Thomas Monjalon Cc: dev@dpdk.org, Shreyansh Jain , Don Provan , Jan Blunck , Hemant Agrawal References: <20170812102220.27773-1-shreyansh.jain@nxp.com> <83a3c6c6-8d50-8106-7c7f-9b5c8263ce96@nxp.com> <9319977.0ApbdN8Evs@xps> Date: Thu, 12 Oct 2017 09:08:27 -0400 In-Reply-To: <9319977.0ApbdN8Evs@xps> (Thomas Monjalon's message of "Thu, 12 Oct 2017 00:34:12 +0200") Message-ID: User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/26.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.38]); Thu, 12 Oct 2017 13:08:29 +0000 (UTC) Subject: Re: [dpdk-dev] [PATCH] eal: bus scan and probe never fail X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 12 Oct 2017 13:08:30 -0000 Thomas Monjalon writes: > 10/10/2017 18:00, Aaron Conole: >> Shreyansh Jain writes: >> >> > Hello Don, >> > >> > On Monday 09 October 2017 11:51 PM, Don Provan wrote: >> >>> -----Original Message----- >> >>> From: Shreyansh Jain [mailto:shreyansh.jain@nxp.com] >> >>> Sent: Monday, October 09, 2017 4:10 AM >> >>> To: Jan Blunck ; Thomas Monjalon >> >>> >> >>> Cc: dev ; Hemant Agrawal >> >>> Subject: Re: [dpdk-dev] [PATCH] eal: bus scan and probe never fail >> >>> >> >>> ... >> >>> This is where I have disagreement/doubt. >> >>> Reporting error code from rte_bus_scan would do two things: >> >>> >> >>> 1. rte_eal_init is not designed to ignore/log-only these errors - it >> >>> would quit initialization. (But, this can be changed) >> >>> 2. What should rte_eal_init do with this error? rte_bus_scan would have >> >>> already printed the problematic bus->scan() failure. >> >> >> >> These practical problems confirm to me that the failure of a bus >> >> scan is more of a strategic issue: when asking "which devices can >> >> I use?", "none" is a perfectly valid answer that does not seem >> >> like an error to me even when a failed bus scan is the reason for >> >> that answer. >> > >> > I agree with this. >> > >> >> >> >> From the application's point of view, the potential error here >> >> is that the device it wants to use isn't available. I don't see that >> >> either the init function or the probe function will have enough >> >> information to understand that application-level problem, so >> >> they should leave it to the application to detect it. >> > >> > I think I understand you comment but just want to cross check again: >> > Scan or probe error should simply be ignored by EAL layer and let the >> > application take stance when it detects that the device it was looking >> > for is missing. Is my understanding correct? >> > >> > I am trying to come a conclusion so that this patch can either be >> > modified or pushed as it is. If the above understanding is correct, I >> > don't see any changes required in the patch. >> >> Does it make sense to introduce a way to query the results of the >> various bus types for their status? That way we can give the relevant >> information to the application if it wants, and make the bus scanning >> code *always* succeed? This version shouldn't be an ABI breakage, >> either (confirm?). >> >> half-baked below (not tested or suitable - just an example): > > We are going to need notification callbacks for scan and probe anyway. > I think errors could be also notified with callbacks? Definitely. That's part of my half-baked patch. Call the error check function and get a callback. There's probably a better way to do it than my patch.