From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Return-Path: MIME-Version: 1.0 Date: Sat, 02 Jun 2018 13:57:19 -0400 From: okaya@codeaurora.org To: Pavel Machek Subject: Re: [PATCH] PCI: Add pci=safemode option In-Reply-To: <20180602174307.GB14870@amd> References: <1527650389-31575-1-git-send-email-okaya@codeaurora.org> <20180530043103.GA19734@kroah.com> <6c317ed8-cca3-8862-5f3b-12cf14e4d53b@codeaurora.org> <20180602174307.GB14870@amd> Message-ID: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Gabriele Paoloni , "open list:DOCUMENTATION" , linux-pci@vger.kernel.org, Keith Busch , Kai-Heng Feng , Ingo Molnar , Christoffer Dall , Jonathan Corbet , timur@codeaurora.org, "Rafael J. Wysocki" , Dongdong Liu , David Rientjes , Thymo van Beers , "Paul E. McKenney" , Frederick Lawler , Konrad Rzeszutek Wilk , Marc Zyngier , linux-arm-msm@vger.kernel.org, Frederic Weisbecker , Bjorn Helgaas , Thomas Gleixner , linux-arm-kernel@lists.infradead.org, Oza Pawandeep , Greg Kroah-Hartman , open list Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+bjorn=helgaas.com@lists.infradead.org List-ID: On 2018-06-02 13:43, Pavel Machek wrote: > Hi! > >> > And you should explain what exactly in PCI is "optional". Who defines >> > this and where is that list and what can go wrong if those options are >> > not enabled? >> >> Bjorn and I discussed the need for such a "safe" mode feature when you >> want to bring up PCI for a platform. You want to turn off everything >> as >> a starter and just stick to bare minimum. >> >> I can add a few words describing them. The goal of this option is to >> keep >> base PCI features with MSI only. Things like PME, AER, ASPM, Extended >> Tags, LTR, Relaxed Ordering, SRIOV are all considered optional. >> safemode >> is certainly not intended for production environments. >> >> I can taint the kernel as a suggestion. > > I don't think tainting is required. even modern platforms should work > in the safe mode. Yeah, concern was getting used to the safe mode and never running the full stack to fix the actual issues like getting away with crappy hardware and firmware. It becomes a support issue for the community. > Pavel _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel