From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [PATCH] PCI: Add pci=safemode option Date: Sat, 2 Jun 2018 19:43:07 +0200 Message-ID: <20180602174307.GB14870@amd> References: <1527650389-31575-1-git-send-email-okaya@codeaurora.org> <20180530043103.GA19734@kroah.com> <6c317ed8-cca3-8862-5f3b-12cf14e4d53b@codeaurora.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="24zk1gE8NUlDmwG9" Return-path: Content-Disposition: inline In-Reply-To: <6c317ed8-cca3-8862-5f3b-12cf14e4d53b@codeaurora.org> Sender: linux-kernel-owner@vger.kernel.org To: Sinan Kaya Cc: Greg Kroah-Hartman , linux-pci@vger.kernel.org, timur@codeaurora.org, linux-arm-msm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Jonathan Corbet , Bjorn Helgaas , Thomas Gleixner , Ingo Molnar , Christoffer Dall , "Paul E. McKenney" , Marc Zyngier , Kai-Heng Feng , Thymo van Beers , Frederic Weisbecker , Konrad Rzeszutek Wilk , David Rientjes , "Rafael J. Wysocki" , Keith Busch , Dongdong Liu List-Id: linux-arm-msm@vger.kernel.org --24zk1gE8NUlDmwG9 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable 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? >=20 > 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. >=20 > 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.=20 >=20 > I can taint the kernel as a suggestion. I don't think tainting is required. even modern platforms should work in the safe mode. Pavel --=20 (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blo= g.html --24zk1gE8NUlDmwG9 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iEUEARECAAYFAlsS1ysACgkQMOfwapXb+vLNGACgvXxEN0Xsaay3KFmc9pcELqNp yN4Al2Wb+Hsizgq51WxdnORdI/5DhSY= =BqMv -----END PGP SIGNATURE----- --24zk1gE8NUlDmwG9--