Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752041AbaKKD7K (ORCPT ); Mon, 10 Nov 2014 22:59:10 -0500 Received: from mail-ig0-f179.google.com ([209.85.213.179]:46045 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751316AbaKKD7H (ORCPT ); Mon, 10 Nov 2014 22:59:07 -0500 Date: Mon, 10 Nov 2014 20:59:02 -0700 From: Bjorn Helgaas To: Prarit Bhargava Cc: linux-pci@vger.kernel.org, Myron Stowe , linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org, Linus Torvalds Subject: Re: [PATCH] pci, add FW_BUG warning to pci= kernel option Message-ID: <20141111035902.GC28161@google.com> References: <1414865479-25792-1-git-send-email-prarit@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1414865479-25792-1-git-send-email-prarit@redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org [+cc lkml, linux-arch, Linus] On Sat, Nov 01, 2014 at 02:11:19PM -0400, Prarit Bhargava wrote: > The kernel should boot PCI without the use of kernel parameters. Display > a FW_BUG warning when pci= is used. > > Cc: Myron Stowe > Cc: linux-pci@vger.kernel.org > Signed-off-by: Prarit Bhargava > --- > drivers/pci/pci.c | 2 ++ > 1 file changed, 2 insertions(+) > > diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c > index 625a4ac..5172060b 100644 > --- a/drivers/pci/pci.c > +++ b/drivers/pci/pci.c > @@ -4515,6 +4515,8 @@ static int __init pci_setup(char *str) > } > str = k; > } > + add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK); > + pr_crit(FW_BUG "The PCI configuration has been overridden thorugh the use of pci=. Please report the issue you are attempting to resolve to your hardware vendor.\n"); My goal is to be able to boot without any "pci=" parameters, so from that perspective, I like this. When people have a problem booting Linux, they often try a variety of things like "pci=assign-busses", "pci=nocrs", "pci=nomsi", "pci=nommconf", "pci=noacpi", etc. If they find something that works, there's a tendency to treat that as a "solution." I'd rather that they report it, so we can try to fix the bug or add a quirk so the *next* person won't have to figure out the right parameters to use. My worry is that there are a few things where Linux isn't smart enough to do the right thing automatically, and I don't think we'll have a good solution in the near future. For example: pci=norom pci=pcie_bus_perf,pcie_bus_safe,etc. pci=cbiosize=... pci=cbmemsize=... pci=resource_alignment=... pci=hpiosize=... pci=hpmemsize=... pci=realloc I don't like the fact that these options exist, but I suspect there are users that do depend on them and might find this warning too aggressive. So I'm interested in opinions on whether this is a good idea at all and whether we should exclude some options from the warning/tainting. Bjorn > return 0; > } > early_param("pci", pci_setup); > -- > 1.7.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-pci" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/