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=-6.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 5A468C43441 for ; Wed, 28 Nov 2018 17:56:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 1A74320665 for ; Wed, 28 Nov 2018 17:56:25 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=agner.ch header.i=@agner.ch header.b="b5pc/RvO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1A74320665 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=agner.ch Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729338AbeK2E6u (ORCPT ); Wed, 28 Nov 2018 23:58:50 -0500 Received: from mail.kmu-office.ch ([178.209.48.109]:45226 "EHLO mail.kmu-office.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728341AbeK2E6t (ORCPT ); Wed, 28 Nov 2018 23:58:49 -0500 Received: from webmail.kmu-office.ch (unknown [IPv6:2a02:418:6a02::a3]) by mail.kmu-office.ch (Postfix) with ESMTPSA id 5C9A25C0D8F; Wed, 28 Nov 2018 18:56:19 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=agner.ch; s=dkim; t=1543427779; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=kP98xifePJOH9xH007JIyp4GU9vk/2zWb3pImuRgfJA=; b=b5pc/RvOdCU1RHfP6mrqriRLdb8ai/TuEopSlGGe9F8rZ27gd8Y7Pfu7xlpCFaVRRgsnHk iuTDVikNQ4LpMugvnUvpvmhTIgzcVo4Z5Bhee/v5L+rFNT8HJH1pQteZNS1mT/cE+iuFTd wor1u52S/MO9VFMZkPYa9StNQrvME1I= MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Date: Wed, 28 Nov 2018 18:56:19 +0100 From: Stefan Agner To: Lucas Stach Cc: Leonard Crestez , lorenzo.pieralisi@arm.com, Trent Piepho , Richard Zhu , linux-kernel@vger.kernel.org, jingoohan1@gmail.com, gustavo.pimentel@synopsys.com, andrew.smirnov@gmail.com, linux-pci@vger.kernel.org, bhelgaas@google.com Subject: Re: [PATCH v3 2/2] PCI: imx6: limit DBI register length In-Reply-To: <1543427438.2507.52.camel@pengutronix.de> References: <20181120165626.26424-1-stefan@agner.ch> <20181120165626.26424-2-stefan@agner.ch> <581b9548043d5276f6685f534386180fd0673a9a.camel@nxp.com> <1542741198.30311.608.camel@impinj.com> <268e109e1c6b309454bd5a313078894c@agner.ch> <1542749302.30311.624.camel@impinj.com> <1543427438.2507.52.camel@pengutronix.de> Message-ID: <52f4ec8b298ec8e672f2dc5bf670b7b5@agner.ch> X-Sender: stefan@agner.ch User-Agent: Roundcube Webmail/1.3.7 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 28.11.2018 18:50, Lucas Stach wrote: > Am Mittwoch, den 28.11.2018, 18:36 +0100 schrieb Stefan Agner: >> On 28.11.2018 13:19, Stefan Agner wrote: >> > On 21.11.2018 14:47, Leonard Crestez wrote: >> > > On 11/20/2018 11:28 PM, Trent Piepho wrote: >> > > > On Tue, 2018-11-20 at 21:42 +0100, Stefan Agner wrote: >> > > > > On 20.11.2018 20:13, Trent Piepho wrote: >> > > > > > It also seems to me that this doesn't need to be in the internal pci >> > > > > > config access functions.  The driver shouldn't be reading registers >> > > > > > that don't exist anyway.  It's really about trying to fix sysfs access >> > > > > > to registers that don't exist.  So maybe it should be done there. >> > > > > >> > > > > That was my first approach, see: >> > > > >> > > > Yes, but that just used the pci device id which applies to every IMX >> > > > design. >> > > > >> > > > It's also not totally correct, as it seems real registers after 0x200 >> > > > do work on imx6, and that would prevent access to them. >> > > >> > > I see that Lorenzo already accepted the patch in pci/dwc: >> > > >> > > https://git.kernel.org/pub/scm/linux/kernel/git/lpieralisi/pci.git/commit/?h=pci/dwc&id=f14eaec153aaebbe940ddd21e4198cc2abc927c2 >> > > >> > > My tests show that this series breaks pci cards on 6qdl and I think it >> > > should be reverted until a fix is found. Are you OK with this? >> > > >> > > Fixing might require an entirely different approach. >> > >> > I tried to reproduce this issue on Apalis iMX6 (i.MX 6Q) with a ath9k >> > PCIe WiFi card, the issue you are seeing did not happen. My lspci looks >> > as follows: >> > >> > root@ea210c63d739:/# lspci -v >> > 00:00.0 PCI bridge: Synopsys, Inc. Device abcd (rev 01) (prog-if 00 >> > [Normal decode]) >> >         Flags: bus master, fast devsel, latency 0, IRQ 255 >> >         Memory at 01000000 (32-bit, non-prefetchable) [size=1M] >> >         Bus: primary=00, secondary=01, subordinate=ff, sec-latency=0 >> >         Memory behind bridge: 01100000-011fffff >> >         [virtual] Expansion ROM at 01200000 [disabled] [size=64K] >> >         Capabilities: [40] Power Management version 3 >> >         Capabilities: [50] MSI: Enable- Count=1/1 Maskable+ 64bit+ >> >         Capabilities: [70] Express Root Port (Slot-), MSI 00 >> >         Capabilities: [100] Advanced Error Reporting >> >         Capabilities: [140] Virtual Channel >> > lspci: Unable to load libkmod resources: error -12 >> > >> > 01:00.0 Network controller: Qualcomm Atheros AR928X Wireless Network >> > Adapter (PCI-Express) (rev 01) >> >         Subsystem: Foxconn International, Inc. Device e007 >> >         Flags: bus master, fast devsel, latency 0, IRQ 312 >> >         Memory at 01100000 (64-bit, non-prefetchable) [size=64K] >> >         Capabilities: [40] Power Management version 2 >> >         Capabilities: [50] MSI: Enable- Count=1/1 Maskable- 64bit- >> >         Capabilities: [60] Express Legacy Endpoint, MSI 00 >> >         Capabilities: [90] MSI-X: Enable- Count=1 Masked- >> >         Capabilities: [100] Advanced Error Reporting >> >         Capabilities: [140] Virtual Channel >> >         Capabilities: [160] Device Serial Number 00-00-00-00-00-00-00-00 >> >         Kernel driver in use: ath9k >> > >> > >> > I did also setup a WiFi network and transmitted some packages, but I did >> > not get a nobody carred message. Do you have an idea why that might be? >> > >> > # cat /proc/interrupts >> > ... >> > 312:      10967          0          0          0       GPC 123 Level     >> > ath9k >> > ... >> > >> > >> > Your conclusion in this thread seem reasonable, hence reverting the >> > issue does. However, I still would like to reproduce the issue so I can >> > make sure that future patches don't break it :-) >> >> Hm, I realized that I need to enable CONFIG_PCIEPORTBUS and set >> ath9k.use_msi=1 to get MSI for that card. However, it seems that ath9k >> does not behave well in that setup. It does get interrupts, and seems to >> work to some degree, but I was not successful in transmitting data over >> WiFi, but that might be an entirly different thing. >> >> However, what I noticed is that when CONFIG_PCIEPORTBUS and >> CONFIG_PCI_MSI is enabled, MSI works but legacy interrupt seem not to >> fire anymore. That is true for ath9k as well as e1000e (using >> e1000e.IntMode=0 to force legacy). Is that a known issue/limitation with >> i.MX 6 PCIe? > > Yes, this is a known issue with the Designware PCIe core, not just on > i.MX6. As soon as any MSI interrupt is enabled, the core doesn't > forward legacy IRQs anymore. Oh I see, unfortunate! > > So if any card in your system needs legacy interrupts (and ath9k is > very likely to need this, as MSI support is pretty new and > experimental), you need to boot with "nomsi" set on the kernel command > line. Ok, thanks for clarification. FWIW, e1000e with MSI works perfectly fine, its just ath9k when forcing MSI using the kernel parameter which does not work really. I guess that is the reason it is not enabled by default. -- Stefan