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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07921C433F5 for ; Fri, 29 Oct 2021 20:27:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id DE2FA61039 for ; Fri, 29 Oct 2021 20:27:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230221AbhJ2UaD (ORCPT ); Fri, 29 Oct 2021 16:30:03 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42562 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229897AbhJ2UaC (ORCPT ); Fri, 29 Oct 2021 16:30:02 -0400 Received: from mail-ua1-x92a.google.com (mail-ua1-x92a.google.com [IPv6:2607:f8b0:4864:20::92a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6C3AAC061570; Fri, 29 Oct 2021 13:27:33 -0700 (PDT) Received: by mail-ua1-x92a.google.com with SMTP id x3so20270342uar.13; Fri, 29 Oct 2021 13:27:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=pqg/kF25IE3Rne+C/OzkoLGPaIYkldAY8r8E8VHOCMA=; b=bnMOeP9UKV5j22QqgzQ60gKvPozViwAWHg4/tjraTKdpHnyuDMwB68wc9gp5Mzampv H28aMMbZzF0WVWPq6GIxpbRciQsA4Pwg1YJ3DfBAUHYT/WBpsmlKtsc/BhwsRonFv8PF UDGxaIGhVWcH0JQR849iZC1e03Qo2oKGifWkRglByLwhwnhWxCtK5saCEP0aBgvl9XmO jZth0xkPECgEOTElbaz9R0+CSi2E2tqak6OYIS6w8xE8b782fOG140liDyPxqpowDcaA jGZX0QjpN2ku85KKLg6g+CxcRFFyPB9KIyMT+3/8gClycWB1XMyhM3N1Hd4W/9Z15obW ccvg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=pqg/kF25IE3Rne+C/OzkoLGPaIYkldAY8r8E8VHOCMA=; b=l6DoNdv1LSkiI3m9z9cwjgEJRhdDs5E6tGuPLw5TyqIKjrZS5SvPM9PAx61EWsRWFt HUd+3Xst8yLEvlCHlDG5LQWcw6ZqvGUVuxGDBH38k4gPrIcVpNIEDoXMizvCypt2Lzny QZvcRz22LJcrXDwUizA4Vjgu32R+74Yk0z9sf6pd400V0zKouwF6NPO4Jk6mpXIsDBo+ uqNEPbPFiI+wSPssh0raj02ZQhiGJ1ekI3gzsm4CW76Ni10iZyM0gApatOM9/6XZIMYU gkil/Frv8ucIpJh7aNnIWecw3+5dCXpkrhcInKs0FTueDufRQ162BIFyiKRCGqy3abij 981A== X-Gm-Message-State: AOAM530EQqRjxkOJ/gkOcBTuAxOmR/iViVYWkaNYRU5rgXwoBj16pspT RQmEctcevXW7vqKV7KAYe1glHS89S9SiqsSChO92IBsQ79U= X-Google-Smtp-Source: ABdhPJxjZ+rsnfCf4Vee/PqzdFgYnFMqI0aY1PJBX3qCSfi+7xTveWV5090iA5r7e+cIPovNX9bCIuRanUZJLTwfsh4= X-Received: by 2002:a05:6102:3ec3:: with SMTP id n3mr15004901vsv.48.1635539252506; Fri, 29 Oct 2021 13:27:32 -0700 (PDT) MIME-Version: 1.0 References: <20211029194751.GA349935@bhelgaas> In-Reply-To: <20211029194751.GA349935@bhelgaas> From: Sergio Paracuellos Date: Fri, 29 Oct 2021 22:27:20 +0200 Message-ID: Subject: Re: [PATCH v2 2/3] MIPS: cm/cpc: export some missing symbols to be able to use them from driver code To: Bjorn Helgaas Cc: Thomas Bogendoerfer , Yanteng Si , Florian Fainelli , bcm-kernel-feedback-list@broadcom.com, Yanteng Si , Stephen Rothwell , Lorenzo Pieralisi , Rob Herring , kw@linux.com, Bjorn Helgaas , Matthias Brugger , Philipp Zabel , linux-pci , linux-arm-kernel@lists.infradead.org, "moderated list:ARM/Mediatek SoC support" , "open list:MIPS" , chenhuacai@kernel.org, sterlingteng@gmail.com, Linux Next Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-next@vger.kernel.org On Fri, Oct 29, 2021 at 9:47 PM Bjorn Helgaas wrote: > > On Fri, Oct 29, 2021 at 09:37:53PM +0200, Sergio Paracuellos wrote: > > On Fri, Oct 29, 2021 at 8:49 PM Bjorn Helgaas wrote: > > > On Fri, Oct 29, 2021 at 07:28:47AM +0200, Sergio Paracuellos wrote: > > > > On Thu, Oct 28, 2021 at 10:47 PM Bjorn Helgaas wrote: > > > > > On Thu, Oct 28, 2021 at 11:59:17AM +0200, Sergio Paracuellos wrote: > > > > > > On Thu, Oct 28, 2021 at 11:34 AM Sergio Paracuellos > > > > > > wrote: > > > > > > > On Thu, Oct 28, 2021 at 11:24 AM Thomas Bogendoerfer > > > > > > > wrote: > > > > > > > > On Thu, Oct 28, 2021 at 06:11:18AM +0200, Sergio Paracuellos wrote: > > > > > > > > > On Thu, Oct 28, 2021 at 6:05 AM Yanteng Si wrote: > > > > > > > > > > > > > > > > > > > > Since commit 2bdd5238e756 ("PCI: mt7621: Add MediaTek MT7621 PCIe host controller driver") > > > > > > > > > > the MT7621 PCIe host controller driver is built as a module but modpost complains once these > > > > > > > > > > drivers become modules. > > > > > > > > > > > > > > > > > > > > ERROR: modpost: "mips_cm_unlock_other" [drivers/pci/controller/pcie-mt7621.ko] undefined! > > > > > > > > > > ERROR: modpost: "mips_cpc_base" [drivers/pci/controller/pcie-mt7621.ko] undefined! > > > > > > > > > > ERROR: modpost: "mips_cm_lock_other" [drivers/pci/controller/pcie-mt7621.ko] undefined! > > > > > > > > > > ERROR: modpost: "mips_cm_is64" [drivers/pci/controller/pcie-mt7621.ko] undefined! > > > > > > > > > > ERROR: modpost: "mips_gcr_base" [drivers/pci/controller/pcie-mt7621.ko] undefined! > > > > > > > > > > > > > > > > > > > > Let's just export them. > > > > > > > > > > > > > > > > > > > > Signed-off-by: Yanteng Si > > > > > > > > > > --- > > > > > > > > > > arch/mips/kernel/mips-cm.c | 5 +++++ > > > > > > > > > > arch/mips/kernel/mips-cpc.c | 1 + > > > > > > > > > > 2 files changed, 6 insertions(+) > > > > > > > > > > > > > > > > > > > > > > > > > > > > Reviewed-by: Sergio Paracuellos > > > > > > > > > > > > > > > > could we instead make the pcie-mt761 driver non modular ? Exporting > > > > > > > > all MIPS specific stuff for just making an essential driver modular > > > > > > > > doesn't IMHO make much sense. > > > > > > > > > > > > > > The driver is modular because I have been advised other times that new > > > > > > > drivers should be able to be compiled as modules and we should avoid > > > > > > > using 'bool' in Kconfig for new drivers. That's the only reason. I am > > > > > > > also always including as 'y' the driver since for me not having pci in > > > > > > > my boards has no sense... I am ok in changing Kconfig to be 'bool' > > > > > > > instead of 'tristate', but I don't know what should be the correct > > > > > > > thing to do in this case. Thoughts? > > > > > > > > > > > > I guess we also want the driver to at least be compile tested in > > > > > > 'allmodconfig' and other similars...15692a80d949 > > > > > > > > > > Sounds like the systems that actually use this driver require it to be > > > > > built-in, and the only benefit of exporting these symbols is that we > > > > > would get better compile test coverage. > > > > > > > > > > If that's the case, I agree that it's better to just make it > > > > > non-modular. > > > > > > > > I agree and that was my reasoning for sending a patch to also convert > > > > to bool the phy driver that this PCIe controller uses. When the pull > > > > request was sent from Vinod to Greg, Greg refused to take it because > > > > of that commit and the commit was reverted and a new pull request was > > > > sent including this revert. This is commit 15692a80d949 ("phy: Revert > > > > "phy: ralink: Kconfig: convert mt7621-pci-phy into 'bool'""). Because > > > > of this I also changed the PCIe controller Kconfig from bool to > > > > tristate when I sent v3 of the series which at the end were the ones > > > > that was finally taken. There are also other ralink related symbols > > > > that have been exported to allow to compile other drivers as a > > > > modules, like the watchdog. See the commit fef532ea0cd8 ("MIPS: > > > > ralink: export rt_sysc_membase for rt2880_wdt.c"). So, as I said, I > > > > agree and I am using the driver as if it were a bool and also ralink > > > > systems normally require all drivers built-in, but I think we have to > > > > take into account also the "historical facts" here. In any case, > > > > Bjorn, let me know if you want me to send whatever patch might be > > > > needed. > > > > > > I didn't see the conversation with Greg, so I don't know the whole > > > story. > > > > Here it is: https://www.spinics.net/lists/kernel/msg3986821.html > > > > > For pcie-mt7621.c, it looks like the only problem is > > > setup_cm_memory_region(), which does a little coherency-related stuff. > > > If we could move that to arch/mips, we could still make this tristate. > > > > Yes, the only mips specific function used in the driver is > > 'setup_cm_memory_region()'. > > > > > One way might be to implement a pcibios_root_bridge_prepare() for mips > > > and put the setup_cm_memory_region() stuff in there. It's not *ideal* > > > because that's a strong/weak function arrangement that doesn't allow > > > for multiple host bridges, but that's probably not an issue here. > > > > > > If we can't do that, I think making it bool is probably the right > > > answer, but it would be worth a brief comment in the commit log to > > > explain the issue. > > > > Do you mean to implement 'pcibios_root_bridge_prepare()' for MIPS > > ralink? I guess this means to parse device tree and so on only to get > > memory range addresses to be added to the MIPS I/O coherence regions > > to make things work and then re-parse it again in the driver to do the > > proper PCI setup... We end up in an arch generic driver but at the end > > this controller is only present in ralink MIPS, so I am not sure that > > implementing 'pcibios_root_bridge_prepare()' is worthy here... I can > > explore and try to implement it if you think that it really makes > > sense... but, IMHO if this is the case, just making it bool looks like > > the correct thing to do. > > It should be trivial to put the contents of setup_cm_memory_region() > into a ralink function called pcibios_root_bridge_prepare(). > > pcibios_root_bridge_prepare() is called with the same "struct > pci_host_bridge *" argument as setup_cm_memory_region(), and it's > called slightly later, so the window resources are already set up, so > no DT parsing is required. It looks like a simple move and rename to > me. I see. Thanks Bjorn. I will try the approach during the weekend and report if it works. Best regards, Sergio Paracuellos > > Bjorn