From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 8 Jan 2016 14:31:02 -0600 From: Bjorn Helgaas To: Paul Gortmaker Cc: Arnd Bergmann , Thierry Reding , Ley Foon Tan , Geert Uytterhoeven , "linux-kernel@vger.kernel.org" , Linux-sh list , linux-pci , Alexandre Courbot , Pratyush Anand , Michal Simek , Kishon Vijay Abraham I , Murali Karicheri , =?iso-8859-1?Q?S=F6ren?= Brinkmann , Jason Cooper , Stephen Warren , Simon Horman , linux-tegra@vger.kernel.org, "linux-omap@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , Thomas Petazzoni , Richard Zhu , Rocketboard Maillist , Bjorn Helgaas , Lucas Stach Subject: Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci* Message-ID: <20160108203102.GH5354@localhost> References: <1449970917-12633-1-git-send-email-paul.gortmaker@windriver.com> <20151214091940.GA15126@ulmo.nvidia.com> <3302340.SIljl1qYTl@wuerfel> <20151215151624.GB2772@windriver.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20151215151624.GB2772@windriver.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: On Tue, Dec 15, 2015 at 10:16:24AM -0500, Paul Gortmaker wrote: > [Re: [PATCH 00/10] drivers/pci: avoid module_init in non-modular host/pci*] On 14/12/2015 (Mon 11:27) Arnd Bergmann wrote: > > > On Monday 14 December 2015 10:19:40 Thierry Reding wrote: > > > > PCIe host driver that use fixup (DECLARE_PCI_FIXUP_*) can't use tristate. > > > > Fixup region is in kernel region and this region if not updated when > > > > loading a module. > > > > > > Interesting, I hadn't thought about that. I suppose this means that the > > > module will end up containing an unused section with the fixup code. It > > > might be useful to add a way for that to trigger a warning at build > > > time. > > > > > > Perhaps to fix this a mechanism could be introduced to add a table of > > > fixups to a host controller driver and that will get applied to all > > > children of the bridge. It could be problematic to cover all of the > > > different fixup stages, though. > > > > I think a lot of the fixups shouldn't really be there in the first place, > > they are about stuff that we can fix up in the probe function, or that should > > be fixed up in the probe function with some appropriate core support added. > > So, the feedback on this is a bit all over the map, leaving me unsure > what to do next. And is the choice we make on a per board/bsp basis or > ideally across all platforms? I see the choices as: > > 1) do nothing; which IMHO is least desirable as it leaves the code > misrepresenting itself as modular; one of the key issues I wanted to fix > > 2) use the patches I've sent ; then as they are genuinely made modular, > the person doing so essentially "patch -R" or reverts the change as > step one. This has the advantage of solving the "we'll get to it > someday" issue if someday never comes. > > 3) make them all tristate; beat it with a stick until it compiles [M] > and modposts -- leaving the fixups and functional testing to people with > the boards and low level knowledge to make it _work_ as a module. The > downside here is the code is still kind of misrepresenting itself as > modularly functional -- a ban of unloading might mitigate that some. I'd like to preserve the mind-set that host controller drivers are *expected* to be modular, even if we aren't there yet. I guess that means I'm in favor of option 3, at least for drivers that don't use fixups. Bjorn