From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 53A77C19F34 for ; Fri, 6 Aug 2021 21:24:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 37175611C5 for ; Fri, 6 Aug 2021 21:24:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241071AbhHFVZL (ORCPT ); Fri, 6 Aug 2021 17:25:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:38082 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240338AbhHFVZJ (ORCPT ); Fri, 6 Aug 2021 17:25:09 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 4064360EE8; Fri, 6 Aug 2021 21:24:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1628285093; bh=OJXVvQV1lg0BTpnm4/Nv7ym7sLl0HIhqKTRdfOznYwg=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=goH/1yJM9CgOOo+OcwLI85KOcKMTJKy8qsbi9kmA/eUKLp96x9J8M/JAw+C0HoXtl LLP9C54GqLgkjnKpGR9kkrYUXUKz/g5bCUA/CpaOzR6XQzlUTgr5y3Dk7zGrmBxX8N en5fOF69mFY7iz78CR1nGEcyNekjfw/CZ0EQbDXeU3Hh82nmIhL0nXS2kQ3mhduoVP XswzHNEybaPpFHtw5KHBi3RP5f5dPsW9v9eFEsYvxzj76KiOdi8Bw4rMEV5B6PvQ1z CLKL2wH1wGanKV5ZinDF8ZSKormkVT85L0UCSY8TizkDvEv+r8Jkclod/etLJWRRFl 2rifLx8uQfKtA== Date: Fri, 6 Aug 2021 16:24:52 -0500 From: Bjorn Helgaas To: Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= Cc: Mark Rutland , Giovanni Cabiddu , =?utf-8?B?UmFmYcWCIE1pxYJlY2tp?= , Peter Zijlstra , linux-pci@vger.kernel.org, Alexander Duyck , Russell Currey , Sathya Prakash , oss-drivers@corigine.com, Paul Mackerras , "H. Peter Anvin" , Jiri Olsa , Boris Ostrovsky , linux-perf-users@vger.kernel.org, Stefano Stabellini , Herbert Xu , linux-scsi@vger.kernel.org, Michael Ellerman , Ido Schimmel , x86@kernel.org, qat-linux@intel.com, Alexander Shishkin , Ingo Molnar , Benjamin Herrenschmidt , linux-wireless@vger.kernel.org, Jakub Kicinski , Mathias Nyman , Yisen Zhuang , Fiona Trahe , Andrew Donnellan , Arnd Bergmann , Konrad Rzeszutek Wilk , Suganath Prabu Subramani , Simon Horman , Arnaldo Carvalho de Melo , Borislav Petkov , Michael Buesch , Jiri Pirko , Bjorn Helgaas , Namhyung Kim , Thomas Gleixner , Andy Shevchenko , Juergen Gross , Salil Mehta , Sreekanth Reddy , xen-devel@lists.xenproject.org, Vadym Kochan , MPT-FusionLinux.pdl@broadcom.com, Greg Kroah-Hartman , linux-usb@vger.kernel.org, Wojciech Ziemba , linux-kernel@vger.kernel.org, Taras Chornyi , Zhou Wang , linux-crypto@vger.kernel.org, kernel@pengutronix.de, netdev@vger.kernel.org, Frederic Barrat , Oliver O'Halloran , linuxppc-dev@lists.ozlabs.org, "David S. Miller" Subject: Re: [PATCH v2 0/6] PCI: Drop duplicated tracking of a pci_dev's bound driver Message-ID: <20210806212452.GA1867870@bjorn-Precision-5520> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210806064623.3lxl4clzbjpmchef@pengutronix.de> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Fri, Aug 06, 2021 at 08:46:23AM +0200, Uwe Kleine-König wrote: > On Thu, Aug 05, 2021 at 06:42:34PM -0500, Bjorn Helgaas wrote: > > I looked at all the bus_type.probe() methods, it looks like pci_dev is > > not the only offender here. At least the following also have a driver > > pointer in the device struct: > > > > parisc_device.driver > > acpi_device.driver > > dio_dev.driver > > hid_device.driver > > pci_dev.driver > > pnp_dev.driver > > rio_dev.driver > > zorro_dev.driver > > Right, when I converted zorro_dev it was pointed out that the code was > copied from pci and the latter has the same construct. :-) > See > https://lore.kernel.org/r/20210730191035.1455248-5-u.kleine-koenig@pengutronix.de > for the patch, I don't find where pci was pointed out, maybe it was on > irc only. Oh, thanks! I looked to see if you'd done something similar elsewhere, but I missed this one. > > Looking through the places that care about pci_dev.driver (the ones > > updated by patch 5/6), many of them are ... a little dubious to begin > > with. A few need the "struct pci_error_handlers *err_handler" > > pointer, so that's probably legitimate. But many just need a name, > > and should probably be using dev_driver_string() instead. > > Yeah, I considered adding a function to get the driver name from a > pci_dev and a function to get the error handlers. Maybe it's an idea to > introduce these two and then use to_pci_driver(pdev->dev.driver) for the > few remaining users? Maybe doing that on top of my current series makes > sense to have a clean switch from pdev->driver to pdev->dev.driver?! I'd propose using dev_driver_string() for these places: eeh_driver_name() (could change callers to use dev_driver_string()) bcma_host_pci_probe() qm_alloc_uacce() hns3_get_drvinfo() prestera_pci_probe() mlxsw_pci_probe() nfp_get_drvinfo() ssb_pcihost_probe() The use in mpt_device_driver_register() looks unnecessary: it's only to get a struct pci_device_id *, which is passed to ->probe() functions that don't need it. The use in adf_enable_aer() looks wrong: it sets the err_handler pointer in one of the adf_driver structs. I think those structs should be basically immutable, and the drivers that call adf_enable_aer() from their .probe() methods should set ".err_handler = &adf_err_handler" in their static adf_driver definitions instead. I think that basically leaves these: uncore_pci_probe() # .id_table, custom driver "registration" match_id() # .id_table, arch/x86/kernel/probe_roms.c xhci_pci_quirks() # .id_table pci_error_handlers() # roll-your-own AER handling, drivers/misc/cxl/guest.c I think it would be fine to use to_pci_driver(pdev->dev.driver) for these few. Bjorn