From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753648AbeCFOZV (ORCPT ); Tue, 6 Mar 2018 09:25:21 -0500 Received: from mail-pl0-f67.google.com ([209.85.160.67]:37740 "EHLO mail-pl0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750817AbeCFOZT (ORCPT ); Tue, 6 Mar 2018 09:25:19 -0500 X-Google-Smtp-Source: AG47ELuotW8qGVEJtcQh/k2a8fVJc3st5K1/t/6lQmZVCLG4yGtG5H3DyEuUROr4bsXX39kGuqagIg== Subject: Re: lost interrupts when running sabrelite images (v4.15+) in qemu To: Troy Kisky Cc: Fugang Duan , netdev@vger.kernel.org, linux-kernel@vger.kernel.org References: <20180303163236.GA29514@roeck-us.net> <88917ab4-ade0-dcfc-e81a-eeaa8a4d15b8@boundarydevices.com> <2801dae5-1334-a127-d36c-244d35e71222@roeck-us.net> <5c5ffdea-7702-c989-0fdb-60803c8e59ab@boundarydevices.com> From: Guenter Roeck Message-ID: <9ee66efa-397c-898a-5cad-64eabc7752b9@roeck-us.net> Date: Tue, 6 Mar 2018 06:25:15 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.6.0 MIME-Version: 1.0 In-Reply-To: <5c5ffdea-7702-c989-0fdb-60803c8e59ab@boundarydevices.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/05/2018 09:30 AM, Troy Kisky wrote: > On 3/3/2018 1:12 PM, Guenter Roeck wrote: >> On 03/03/2018 12:48 PM, Guenter Roeck wrote: >>> On 03/03/2018 11:07 AM, Troy Kisky wrote: >>>> On 3/3/2018 8:32 AM, Guenter Roeck wrote: >>>>> Hi, >>>>> >>>>> since v4.15, I get the following runtime warning when running sabrelite images >>>>> in qemu. >>>>> >>>>> irq 65: nobody cared (try booting with the "irqpoll" option) >>>>> ... >>>>> handlers: >>>>> [<26292474>] fec_pps_interrupt >>>>> Disabling IRQ #65 >>>>> fec 2188000.ethernet (unnamed net_device) (uninitialized): MDIO read timeout >>>>> >>>>> Bisect points to commit 4ad1ceec05e491 ("net: fec: Let fec_ptp have its >>>>> own interrupt routine"). Analysis shows that platform_irq_count() >>>>> returns 2, which is reduced to 1 by fec_enet_get_irq_cnt(). >>>>> If I let fec_enet_get_irq_cnt() return 2, the problem is gone. >>>>> Reverting commit 4ad1ceec05e491 also fixes the problem. >>>>> >>>>> Bisect log is attached. >>>>> >>>> >>>> Sounds like you found a bug with qemu. I just booted sabrelite over nfs fine. >>>> My interrupts look like this. >>>> >>>> >>>>   64:      98767          0          0          0     GIC-0 150 Level     2188000.ethernet >>>>   65:          0          0          0          0     GIC-0 151 Level     2188000.ethernet >>>> ___________ >>>> Irq 65 is only for ptp interrrupts now. If qemu is signaling an tx/rx frame interrupt on 65, >>>> then qemu is wrong. Of course, I've never used qemu so feel free to ignore me if I make no sense. >>>> >>> >>> Thanks for checking with real hardware. >>> >>> This is what I see (with your patch reverted): >>> >>>   64:          0     GIC-0 150 Level     2188000.ethernet >>>   65:         64     GIC-0 151 Level     2188000.ethernet >>> >>> Looking into the qemu source, I see: >>> >>> #define FSL_IMX6_ENET_MAC_1588_IRQ 118 >>> #define FSL_IMX6_ENET_MAC_IRQ 119 >>> >>> FSL_IMX6_ENET_MAC_IRQ is then connected to fec interrupt index 0, and FSL_IMX6_ENET_MAC_1588_IRQ >>> is connected to fec interrupt index 1. >>> >>> This may suggest that the defines are reversed. I'll see what happens if I swap them. >>> >> >> Confirmed. If I swap the above defines, everything works fine. At the same time, >> the modified qemu works with older kernels. >> >> Thanks a lot for the hint, and sorry for the noise. >> >> Guenter >> > It definitely was not noise. I bet it helps people searching the mailing list in the future. > Thanks for posting the resolution. > Turns out "works" as I stated above is not entirely accurate. - v4.13 and later work - In v4.12 and earlier, the Ethernet interface fails to instantiate with fec 2188000.ethernet (unnamed net_device) (uninitialized): MDIO read timeout fec: probe of 2188000.ethernet failed with error -5 I have not found the reason yet. Unmodified qemu works fine. - v4.1 and earlier crash. The crash is fixed by commit 32cba57ba74be ("net: fec: introduce fec_ptp_stop and use in probe fail path") There is also a matching bug at lauchpad: https://bugs.launchpad.net/qemu/+bug/1753309 Guenter