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=-6.6 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 A4061C41604 for ; Tue, 6 Oct 2020 08:32:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B4E620789 for ; Tue, 6 Oct 2020 08:32:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vTOdXUmD" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1725943AbgJFIcE (ORCPT ); Tue, 6 Oct 2020 04:32:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37102 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725891AbgJFIcE (ORCPT ); Tue, 6 Oct 2020 04:32:04 -0400 Received: from mail-pg1-x52f.google.com (mail-pg1-x52f.google.com [IPv6:2607:f8b0:4864:20::52f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C03EC061755 for ; Tue, 6 Oct 2020 01:32:03 -0700 (PDT) Received: by mail-pg1-x52f.google.com with SMTP id h6so6911973pgk.4 for ; Tue, 06 Oct 2020 01:32:03 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=pmocHDYYuo/sFME5FMjrvVa/E/+jVJBXTqktpmuPaiE=; b=vTOdXUmDy53kPM78Eqv1ZfpsV/iw2Mo5n9R+7zAP2Xu/nOp3HakjY6yrCIfQzer0M0 HU6QZ+yM/fBXbm7mMtEkS4l08sM/7sNc0pVn0IueBPIjJyl5aYN0WB5h/C8bqbjj/tZk tUI1yD35lu0C33si/ihfM+f+UiPrbvF+W87zD4Qeancs+XghbH2iGLV+94B9BIpC14DY U7fi9NjbhN2HUsJW9td+AlXXkaEQ/puFaBeqDpcz/qA4wFidsQUpeRr9Tpg5QdxmCoXL sFBcCzam6Y5jt8emTxo2HbuE3VpDRC5G1cVIZUPppkoh+WL713Fcp5l0V6xOFXW1kkq4 kt/w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=pmocHDYYuo/sFME5FMjrvVa/E/+jVJBXTqktpmuPaiE=; b=HFBDb5YYJ6b9F9yF+hcMZmEEoYfUqmI3Z2ppNY0dM0FCzJudAdnebxhvRZEDVaP2yU ZlXtNTHyvxbOOFl6gJ860nJGYdCUKdvRJVVY77D1u7Tiul3PUl90jpR2O2p9LIkE+E7G TBjfUuEyQsA2Qc+g4xcDaHGCSNcZ/hOittedLY+eA8jr14/Pk941Ly6v2n3D0ZNxy8Go i++faYD7azrd0V9MRlOZZq6yda4uQKgdssA+Qe9YNXeHMPD794kAcRsa4kq5Og3reCOP CqPav9pBdZlwVw8MGKWuzDLUZxj0C1CbnB5AowKMGlZLxoDMRvitRq69T3m/02TYRGDz 8t/A== X-Gm-Message-State: AOAM532UhudJ8qksXS9vbj/oYNaLCjpTJcYely4bN1bs1eXHIrnyNLMm FzUln8iriNX79iILHX2mxZ8= X-Google-Smtp-Source: ABdhPJzylC9/7Qx+QYTsGUIvgOI3jIRQkcdoboorDshtlqR0WABWcZs6FZI5TP6wTSP+PuoIEfeCow== X-Received: by 2002:a63:c342:: with SMTP id e2mr3075830pgd.56.1601973123042; Tue, 06 Oct 2020 01:32:03 -0700 (PDT) Received: from localhost ([2001:e42:102:1532:160:16:113:140]) by smtp.gmail.com with ESMTPSA id n7sm2621657pfq.114.2020.10.06.01.32.01 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 06 Oct 2020 01:32:02 -0700 (PDT) From: Coiby Xu X-Google-Original-From: Coiby Xu Date: Tue, 6 Oct 2020 16:31:57 +0800 To: Hans de Goede Cc: Linus Walleij , "open list:GPIO SUBSYSTEM" , wang jun , Nehal Shah , Shyam Sundar S K , linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Message-ID: <20201006083157.3pg6zvju5buxspns@Rk> References: <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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org On Tue, Oct 06, 2020 at 08:28:40AM +0200, Hans de Goede wrote: >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. > Disabling the glitch filter works like a charm! Other enthusiastic Linux users who have been troubled by this issue for months would also feel great to know this small tweaking could bring their touchpad back to life:) Thank you! $ git diff diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c index 9a760f5cd7ed..e786d779d6c8 100644 --- a/drivers/pinctrl/pinctrl-amd.c +++ b/drivers/pinctrl/pinctrl-amd.c @@ -463,7 +463,7 @@ static int amd_gpio_irq_set_type(struct irq_data *d, unsigned int type) pin_reg &= ~(ACTIVE_LEVEL_MASK << ACTIVE_LEVEL_OFF); pin_reg |= ACTIVE_LOW << ACTIVE_LEVEL_OFF; pin_reg &= ~(DB_CNTRl_MASK << DB_CNTRL_OFF); - pin_reg |= DB_TYPE_PRESERVE_HIGH_GLITCH << DB_CNTRL_OFF; + /** pin_reg |= DB_TYPE_PRESERVE_HIGH_GLITCH << DB_CNTRL_OFF; */ irq_set_handler_locked(d, handle_level_irq); break; I will learn more about the glitch filter and the implementation of pinctrl and see if I can disable glitch filter only for this touchpad. >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 >> > -- Best regards, Coiby