From: Coiby Xu <coiby.xu@gmail.com> To: Hans de Goede <hdegoede@redhat.com> Cc: Linus Walleij <linus.walleij@linaro.org>, "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>, Nehal Shah <Nehal-bakulchandra.Shah@amd.com>, Shyam Sundar S K <Shyam-sundar.S-k@amd.com>, 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? Date: Sat, 3 Oct 2020 06:45:02 +0800 [thread overview] Message-ID: <20201002224502.vn3ooodrxrblwauu@Rk> (raw) In-Reply-To: <eed704f5-4210-788c-37b7-06d65b58d3de@redhat.com> 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: > ><snip> > >>>>>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, <IRQ> 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 </IRQ> 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 alone 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. I've reverted commit ba714a9c1dea85e0bf2899d02dfeb9c70040427c ("pinctrl/amd: Use regular interrupt instead of chained") to bring back chained interrupt to see if "an irq storm" would happen which seems to be what I need since currently IRQ#7 only fires ~7 times per second. The results is the interrupts arrive in pairs. The time internal between two interrupts in a pair is ~0.0016s but the time internal between interrupt pairs is still ~0.12s (~8Hz). I can't understand this kind of behaviour. This GPIO chip acts like a black box to me. That's also why I ask for other ways to debug amd-pinctrl here in the hope I could understand why the time internal between the two interrupts in a par is much shorter thus to find a way to let IRQ#7 fires much more frequently. >Regards, > >Hans > -- Best regards, Coiby
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From: Coiby Xu <coiby.xu@gmail.com> To: Hans de Goede <hdegoede@redhat.com> Cc: "open list:GPIO SUBSYSTEM" <linux-gpio@vger.kernel.org>, Linus Walleij <linus.walleij@linaro.org>, Shyam Sundar S K <Shyam-sundar.S-k@amd.com>, Nehal Shah <Nehal-bakulchandra.Shah@amd.com>, linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [Linux-kernel-mentees] Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Date: Sat, 3 Oct 2020 06:45:02 +0800 [thread overview] Message-ID: <20201002224502.vn3ooodrxrblwauu@Rk> (raw) In-Reply-To: <eed704f5-4210-788c-37b7-06d65b58d3de@redhat.com> 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: > ><snip> > >>>>>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, <IRQ> 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 </IRQ> 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 alone 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. I've reverted commit ba714a9c1dea85e0bf2899d02dfeb9c70040427c ("pinctrl/amd: Use regular interrupt instead of chained") to bring back chained interrupt to see if "an irq storm" would happen which seems to be what I need since currently IRQ#7 only fires ~7 times per second. The results is the interrupts arrive in pairs. The time internal between two interrupts in a pair is ~0.0016s but the time internal between interrupt pairs is still ~0.12s (~8Hz). I can't understand this kind of behaviour. This GPIO chip acts like a black box to me. That's also why I ask for other ways to debug amd-pinctrl here in the hope I could understand why the time internal between the two interrupts in a par is much shorter thus to find a way to let IRQ#7 fires much more frequently. >Regards, > >Hans > -- Best regards, Coiby _______________________________________________ Linux-kernel-mentees mailing list Linux-kernel-mentees@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/linux-kernel-mentees
next prev parent reply other threads:[~2020-10-02 22:45 UTC|newest] Thread overview: 84+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-10-01 13:22 Any other ways to debug GPIO interrupt controller (pinctrl-amd) for broken touchpads of a new laptop model? Coiby Xu 2020-10-01 13:22 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-01 20:57 ` Linus Walleij 2020-10-01 20:57 ` [Linux-kernel-mentees] " Linus Walleij 2020-10-02 9:40 ` Hans de Goede 2020-10-02 9:40 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 12:42 ` Coiby Xu 2020-10-02 12:42 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 13:36 ` Hans de Goede 2020-10-02 13:36 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 14:51 ` Coiby Xu 2020-10-02 14:51 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 19:44 ` Hans de Goede 2020-10-02 19:44 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-02 22:45 ` Coiby Xu [this message] 2020-10-02 22:45 ` Coiby Xu 2020-10-03 13:22 ` Hans de Goede 2020-10-03 13:22 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-03 23:03 ` Coiby Xu 2020-10-03 23:03 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-04 5:16 ` Coiby Xu 2020-10-04 5:16 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 4:49 ` Coiby Xu 2020-10-06 4:49 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 6:28 ` Hans de Goede 2020-10-06 6:28 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 8:31 ` Coiby Xu 2020-10-06 8:31 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 8:55 ` Hans de Goede 2020-10-06 8:55 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 9:28 ` Hans de Goede 2020-10-06 9:28 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-06 9:29 ` Hans de Goede 2020-10-06 9:29 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-08 16:32 ` Coiby Xu 2020-10-08 16:32 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 4:24 ` Coiby Xu 2020-10-14 4:24 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 11:34 ` Coiby Xu 2020-10-14 11:34 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-14 11:46 ` Hans de Goede 2020-10-14 11:46 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-15 3:27 ` Coiby Xu 2020-10-15 3:27 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-15 4:06 ` Coiby Xu 2020-10-15 4:06 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-26 22:54 ` Coiby Xu 2020-10-26 22:54 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-27 9:52 ` Andy Shevchenko 2020-10-27 9:52 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-30 4:58 ` Coiby Xu 2020-10-30 4:58 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-27 10:09 ` Hans de Goede 2020-10-27 10:09 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-27 15:13 ` Andy Shevchenko 2020-10-27 15:13 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-27 16:00 ` Hans de Goede 2020-10-27 16:00 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-27 16:09 ` Andy Shevchenko 2020-10-27 16:09 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-10-29 8:04 ` Mika Westerberg 2020-10-29 8:04 ` [Linux-kernel-mentees] " Mika Westerberg 2020-10-30 4:54 ` Coiby Xu 2020-10-30 4:54 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-02 19:06 ` Andy Shevchenko 2020-11-02 19:06 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-11-02 22:56 ` Coiby Xu 2020-11-02 22:56 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-03 0:05 ` Coiby Xu 2020-11-03 0:05 ` [Linux-kernel-mentees] " Coiby Xu 2020-11-03 10:12 ` Hans de Goede 2020-11-03 10:12 ` [Linux-kernel-mentees] " Hans de Goede 2020-11-03 10:49 ` Andy Shevchenko 2020-11-03 10:49 ` [Linux-kernel-mentees] " Andy Shevchenko 2020-11-03 11:00 ` Hans de Goede 2020-11-03 11:00 ` [Linux-kernel-mentees] " Hans de Goede 2020-10-08 16:26 ` Coiby Xu 2020-10-08 16:26 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-06 9:16 ` Linus Walleij 2020-10-06 9:16 ` [Linux-kernel-mentees] " Linus Walleij 2020-10-08 16:40 ` Coiby Xu 2020-10-08 16:40 ` [Linux-kernel-mentees] " Coiby Xu 2020-10-02 10:59 ` Coiby Xu 2020-10-02 10:59 ` [Linux-kernel-mentees] " Coiby Xu
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