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 7D820C433B4 for ; Tue, 11 May 2021 04:26:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4506561926 for ; Tue, 11 May 2021 04:26:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229900AbhEKE1q (ORCPT ); Tue, 11 May 2021 00:27:46 -0400 Received: from mail.kernel.org ([198.145.29.99]:44766 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229809AbhEKE1q (ORCPT ); Tue, 11 May 2021 00:27:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 49F7B61924; Tue, 11 May 2021 04:26:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620707200; bh=wRXSAlpFD5A3K59gxjiDb9yv86dHCRapJK897k/KZVM=; h=References:In-Reply-To:From:Date:Subject:To:Cc:From; b=l14XsSKl9CxxOWYR42hUKlBFXXCqRsNU0iQ4lXBq84RT8rQETaimZfDzd2C1O3cJ8 ygzYxkJuXRaxvAlaso+ih1MmvzmUQGvQdB/p5jgvZE4b3agkOHQbIIg/+6PvbfAD9B aK+EBGI6IftrjECs634bxCoLoY8Q2ZFKFH5YN1xXgO+yrZIo+MsvOaeF4Y96Rzd4/9 /YakEPdViMqYioKWHCcUCPmXwEfFna+c9tHKT7HMCEr1FGdJgUqOKUcaKRD3hOe1Ss Ir3in3DzvZsc60STYQByK6eRJGTYKK6UHT9gRCeGoNrIsnYrOm+4B+9WRJ7uMinmKw XdR5n98ZXteUA== Received: by mail-ot1-f54.google.com with SMTP id t4-20020a05683014c4b02902ed26dd7a60so6309424otq.7; Mon, 10 May 2021 21:26:40 -0700 (PDT) X-Gm-Message-State: AOAM533QfxNr6mtt6RnQOf7S82HlyVDUZfzouF8plRJz3e3ssQRj+y0q 8rTbLN7QGHU04tDWqL6zvJMN3ynUp+rgOwbC7VA= X-Google-Smtp-Source: ABdhPJxIuXe2hgWJqDZi6HFqhc1wS2t8jnlgjjTQXKEZ+ZD0Ui2Gc8hVEmFRQk0JpLMfEp9szwbdJXyk0wvSepFglJw= X-Received: by 2002:a9d:69c5:: with SMTP id v5mr23927948oto.108.1620707199581; Mon, 10 May 2021 21:26:39 -0700 (PDT) MIME-Version: 1.0 References: <20210511021656.17719-1-ansuelsmth@gmail.com> In-Reply-To: From: Ard Biesheuvel Date: Tue, 11 May 2021 06:26:28 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] arm: Enlarge IO_SPACE_LIMIT needed for some SoC To: Ansuel Smith Cc: Matthew Wilcox , Russell King , Jonathan Corbet , Linus Walleij , Florian Fainelli , Abbott Liu , Luis Chamberlain , Palmer Dabbelt , Linux Doc Mailing List , Linux Kernel Mailing List , Linux ARM Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org On Tue, 11 May 2021 at 04:32, Ansuel Smith wrote: > > On Tue, May 11, 2021 at 03:24:29AM +0100, Matthew Wilcox wrote: > > On Tue, May 11, 2021 at 04:16:54AM +0200, Ansuel Smith wrote: > > > Ipq8064 SoC requires larger IO_SPACE_LIMIT on second and third pci port. > > > > Do you really? I mean, yes, theoretically, I understand it, the > > hardware supports 64kB of I/O port space per root port. But I/O > > port space is rather deprecated these days. My laptop has precisely > > two devices with I/O ports, one with 64 bytes and the other with 32 > > bytes. Would you really suffer by allocating 16kB of I/O port > > space to each root port? > > We were talking about this in the other wrong patch. I also think this > much space looks wrong. The current ipq806x dts have this space so it's > actually broken from a long time. The only reason pci worked before was > because the pci driver didn't actually check if the settings were right. > New kernel introduced more checks and this problem showed up. (to be > more precise, the pci port are commonly used by the ath10k wifi and the > second ath10k wifi fails to init because of this problem) > If you can give me any hint on how to check if the space can be reduced > I would be very happy to investigate it. > In the driver I notice that the max buffer is set to 2k, could be this a > hint? > Could you share the output of lspci -vv from such a system? I agree with Matthew that fiddling with the size of the I/O space range probably papers over another problem, and with the odd exception, no PCIe card used on ARM systems actually uses their I/O BARs, even when they have them. (I used to carry a PCIe serial port card to UEFI plugfests because that was the only thing that would stop working if a system configured its I/O resource window incorrectly)