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=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 BF60BC41604 for ; Tue, 6 Oct 2020 06:28:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4ED9C20796 for ; Tue, 6 Oct 2020 06:28:48 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="YsDHSUVt" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726761AbgJFG2s (ORCPT ); Tue, 6 Oct 2020 02:28:48 -0400 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:49325 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725962AbgJFG2r (ORCPT ); Tue, 6 Oct 2020 02:28:47 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1601965725; 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=B1QwREq0y9kxw73/YPlBeF9wLu9Bg4SvS+ntbKXf8ro=; b=YsDHSUVtlRq6G8a49qkc3jACS9S99UAKsDZmT7riDvN/bDevvJM0UoworXJI9Wxx9T/kwQ 7CCPlrjzIWjAX1JAkRoHWf4be8sWWai5qQlnbZicIIZTxizoC/o++7oDCAF17ks+N4KQkZ GTdp9OeZbazOwKdXXjULlCbnEMZpY0A= Received: from mail-ed1-f72.google.com (mail-ed1-f72.google.com [209.85.208.72]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-123-hyQU1Ay2Onu4OJ8iv0ZQDQ-1; Tue, 06 Oct 2020 02:28:44 -0400 X-MC-Unique: hyQU1Ay2Onu4OJ8iv0ZQDQ-1 Received: by mail-ed1-f72.google.com with SMTP id f19so5302427edx.18 for ; Mon, 05 Oct 2020 23:28:43 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=B1QwREq0y9kxw73/YPlBeF9wLu9Bg4SvS+ntbKXf8ro=; b=eeR/5x1ee0+yVx74iXmfXqtg5GJmYhyXKJZZIhVzbOpU1yjhOxbkxQ/aueThMGkHjU QsJMpvVH1gztCy8/soFXJCL9WhG4XS8rix7WRkvVW+fv6sq14SwBufietvjhysdxpu1w cXJCiUpV+kbp7fvOKKbVIksEq2MZRnZxwsAtWhYIamOgmsWw2ixbMfK8zugPkdxfhQAm km+cVJT/i4KnlAfbixuZBH4Eak3Edz3DXbZA+ABPX7DLgL9LSHzlr5nQgvpFqMMGMgQq NFveHPNlNK9lQfAQKhsLSCcGlmC7hoYRvqGgZMCUGprtyIIrDP2HujM3M5TA5ZKKVwxR 2tQg== X-Gm-Message-State: AOAM531/A0iB30lwraG1B9bvXjHk0DoTchE7hE1qJBqjw77x/BJ9a2N4 k4dEgHiKjmkCoGcKz5+jbdZWP+gfkvipxCKTSJ29ZNeQUB3zwVpgRVyDMN54QiWXxhO++NJxEWo 5v4nyb1Lcph6ZUR/pTZZX5g== X-Received: by 2002:a17:907:104f:: with SMTP id oy15mr3650537ejb.261.1601965722749; Mon, 05 Oct 2020 23:28:42 -0700 (PDT) X-Google-Smtp-Source: ABdhPJxyZS3P6Oh+XRK/p67YJIRT/oRsPUdOV2clxFth3LomOFXoGdgoONHKeMpo/z/uma3nEj/N3Q== X-Received: by 2002:a17:907:104f:: with SMTP id oy15mr3650511ejb.261.1601965722442; Mon, 05 Oct 2020 23:28:42 -0700 (PDT) Received: from x1.localdomain (2001-1c00-0c0c-fe00-d2ea-f29d-118b-24dc.cable.dynamic.v6.ziggo.nl. [2001:1c00:c0c:fe00:d2ea:f29d:118b:24dc]) by smtp.gmail.com with ESMTPSA id t4sm1385333ejj.6.2020.10.05.23.28.41 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 05 Oct 2020 23:28:41 -0700 (PDT) Subject: Re: Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? To: Coiby Xu , Linus Walleij Cc: "open list:GPIO SUBSYSTEM" , wang jun , Nehal Shah , Shyam Sundar S K , linux-kernel-mentees@lists.linuxfoundation.org References: <3ded544f-be1b-8dc4-16b7-42172b1e1b08@redhat.com> <20201002124235.nhjzq7i4gpkzwgbs@Rk> <39f03cfe-0e7f-2ab6-7821-048cfcde8baa@redhat.com> <20201002145133.a43ypm2z7ofgtt7u@Rk> <20201002224502.vn3ooodrxrblwauu@Rk> <34cecd8e-ffa7-c2bc-8ce3-575db47ff455@redhat.com> <20201003230340.42mtl35n4ka4d5qw@Rk> <20201004051644.f3fg2oavbobrwhf6@Rk> <20201006044941.fdjsp346kc5thyzy@Rk> From: Hans de Goede Message-ID: Date: Tue, 6 Oct 2020 08:28:40 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20201006044941.fdjsp346kc5thyzy@Rk> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi, On 10/6/20 6:49 AM, Coiby Xu wrote: > Hi Hans and Linus, > > I've found the direct evidence proving the GPIO interrupt controller is > malfunctioning. > > I've found a way to let the GPIO chip trigger an interrupt by accident > when playing with the GPIO sysfs interface, > >  - export pin130 which is used by the touchad >  - set the direction to be "out" >  - `echo 0 > value` will trigger the GPIO controller's parent irq and >    "echo 1 > value" will make it stop firing > > (I'm not sure if this is yet another bug of the GPIO chip. Anyway I can > manually trigger an interrupt now.) > > I wrote a C program is to let GPIO controller quickly generate some > interrupts then disable the firing of interrupts by toggling pin#130's > value with an specified time interval, i.e., set the value to 0 first > and then after some time, re-set the value to 1. There is no interrupt > firing unless time internal > 120ms (~7Hz). This explains why we can > only see 7 interrupts for the GPIO controller's parent irq. That is a great find, well done. > My hypothesis is the GPIO doesn't have proper power setting so it stays > in an idle state or its clock frequency is too low by default thus not > quick enough to read interrupt input. Then pinctrl-amd must miss some > code to configure the chip and I need a hardware reference manual of this > GPIO chip (HID: AMDI0030) or reverse-engineer the driver for Windows > since I couldn't find a copy of reference manual online? What would you > suggest? This sounds like it might have something to do with the glitch filter. The code in pinctrl-amd.c to setup the trigger-type also configures the glitch filter, you could try changing that code to disable the glitch-filter. The defines for setting the glitch-filter bits to disabled are already there. Regards, Hans > > Thank you! > > On Sun, Oct 04, 2020 at 01:16:44PM +0800, Coiby Xu wrote: >> On Sun, Oct 04, 2020 at 07:03:40AM +0800, Coiby Xu wrote: >>> On Sat, Oct 03, 2020 at 03:22:46PM +0200, Hans de Goede wrote: >>>> Hi, >>>> >>>> On 10/3/20 12:45 AM, Coiby Xu wrote: >>>>> On Fri, Oct 02, 2020 at 09:44:54PM +0200, Hans de Goede wrote: >>>>>> Hi, >>>>>> >>>>>> On 10/2/20 4:51 PM, Coiby Xu wrote: >>>>>>> On Fri, Oct 02, 2020 at 03:36:29PM +0200, Hans de Goede wrote: >>>>>> >>>>>> >>>>>> >>>>>>>>>> So are you seeing these 7 interrupts / second for the touchpad irq or for >>>>>>>>>> the GPIO controllers parent irq ? >>>>>>>>>> >>>>>>>>>> Also to these 7 interrupts/sec stop happening when you do not touch the >>>>>>>>>> touchpad ? >>>>>>>>>> >>>>>>>>> I see these 7 interrupts / second for the GPIO controller's parent irq. >>>>>>>>> And they stop happening when I don't touch the touchpad. >>>>>>>> >>>>>>>> Only from the parent irq, or also on the touchpad irq itself ? >>>>>>>> >>>>>>>> If this only happens on the parent irq, then I would start looking at the >>>>>>>> amd-pinctrl code which determines which of its "child" irqs to fire. >>>>>>> >>>>>>> This only happens on the parent irq. The input's pin#130 of the GIPO >>>>>>> chip is low most of the time and pin#130. >>>>>> >>>>>> Right, but it is a low-level triggered IRQ, so when it is low it should >>>>>> be executing the i2c-hid interrupt-handler. If it is not executing that >>>>>> then it is time to look at amd-pinctrl's irq-handler and figure out why >>>>>> that is not triggering the child irq handler for the touchpad. >>>>>> >>>>> I'm not sure if I have some incorrect understandings about GPIO >>>>> interrupt controller because I don't quite follow your reasoning. >>>>> What I actually suspect is there's something wrong with amd-pinctrl >>>>> which makes the GPIO chip fail to assert its common interrupt output >>>>> line connected to one IO-APIC's pin#7 thus IRQ#7 fails to fire. What >>>>> I learn about this low-level triggered IRQ is that the i2c-hid >>>>> interrupt-handler will be woken up by amd-pinctrl's irq-handler which >>>>> is executed when the parent IRQ#7 fires. The code path is as follows, >>>>> >>>>>     >>>>>     dump_stack+0x64/0x88 >>>>>     __irq_wake_thread.cold+0x9/0x12 >>>>>     __handle_irq_event_percpu+0x80/0x1c0 >>>>>     handle_irq_event+0x58/0xb0 >>>>>     handle_level_irq+0xb7/0x1a0 >>>>>     generic_handle_irq+0x4a/0x60 >>>>>     amd_gpio_irq_handler+0x15f/0x1b0 [pinctrl_amd] >>>>>     __handle_irq_event_percpu+0x45/0x1c0 >>>>>     handle_irq_event+0x58/0xb0 >>>>>     handle_fasteoi_irq+0xa2/0x210 >>>>>     do_IRQ+0x70/0x120 >>>>>     common_interrupt+0xf/0xf >>>>>     >>>>> >>>>> But the problem is somehow IRQ#7 doesn't even fire when the input's >>>>> pin#130 of the GIPO is low. Without IRQ#7 firing, amd-pinctrl's >>>>> irq-handler wouldn't be executed in the first place, let alonet >>>>> triggering the child irq handler. Btw, amd-pinctrl's irq-handler >>>>> simply iterate over all pins. If there is mapped irq found for this >>>>> hwirq (yes, it won't even check if this pin triggers the interrupt), >>>>> then it will call generic_handle_irq. So there's nothing wrong about >>>>> this part of code. >>>> >>>> Ok, so the i2c-hid irq does fire, but only 7 times a second just >>>> like the GPIO controller's parent irq. >>>> >>> I'm not sure if it's correct to say if hi2c-hid irq fires or not and how >>> frequently it fires since the i2c-hid irq is mapped to pin#130 of the >>> GPIO interrupt controller and the touchpad has another interrupt line >>> connected to pin#130 which fires to indicate new data. All we know is >>> pin#130 of the GPIO chip has low input most of the time when the finger >>> is on the touchpad so we can infer the touchpad has been trying to >>> notify the kernel of new data but somehow GPIO's parent irq only fires 7 >>> times / second. >>> >>>> The only thing I can think of then is to add printk-s to check how >>>> long the i2c-hid interrupt handler takes to complete. It could be >>>> there is a subtle bug somewhere causing the i2c transfers to take >>>> longer when run from a (threaded) irq handler. That would be weird >>>> though, so I don't expect this to result in any useful findings. >>>> >>> >>> I also doubted if it takes too much time for the i2c-hid handler to >>> finish reading i2c transfer, processing data and delivering to the input >>> system. After measuring the time internal between the starting of the >>> GPIO irq's parent handler and when pin#130 is unmasked, we can exclude >>> this possibility. >>> >>> I have been wondering if we let make pin#130 have low input thus to >>> trigger a interrupt firing or assert the GPIO's common interrupt output >>> line manually thus we can measure how long does it take for the kernel >>> to receive the signal. But once GPIO's pin is programmed to be a >>> interrupt line we can't write anything to it and it seems other >>> interrupts can only be generated by the hardware. So this idea is not >>> plausible >>> >> >> Btw, there are other users who have the same laptop model but with a >> different touchpad (ELAN). Their touchpads would show in >> /proc/bus/input/devices but are completely dead. hid-recorder which >> will read HID reports from /dev/hidraw gets nothing if they put there >> fingers on the touchpad but the polling mode could also save their >> touchpads. It seems GPIO controller's parent irq for the ELAN touchpad >> doesn't even fire once. And unlike GPIO, IO-APIC has also be used by >> other devices like the keyboard. So maybe it's safe to assert the root >> cause is from the GPIO controller. >> >>>> Other then that I'm all out of ideas I'm afraid. >>>> >>> Thank you for taking time to investigate this issue anyway! Have a nice >>> weekend:) >>>> Regards, >>>> >>>> Hans >>>> >>> >>> -- >>> Best regards, >>> Coiby >> >> -- >> Best regards, >> Coiby > > -- > Best regards, > Coiby >