Re: [PATCH 2/2] Revert "Input: soc_button_array - debounce the buttons"
From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Date: 2025-06-25 15:10:35
Also in:
linux-acpi, linux-gpio, lkml
On Wed, Jun 25, 2025 at 03:02:18PM +0000, Limonciello, Mario wrote:
On 6/25/25 9:41 AM, Mario Limonciello wrote:quoted
On 6/25/25 9:31 AM, Hans de Goede wrote:quoted
On 25-Jun-25 4:09 PM, Mario Limonciello wrote:quoted
On 6/25/25 4:09 AM, Hans de Goede wrote:quoted
On 24-Jun-25 10:22 PM, Mario Limonciello wrote:
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Ok, so specifically the gpiod_set_debounce() call with 50 ms done by gpio_keys.c is the problem I guess?Yep.quoted
So amd_gpio_set_debounce() does accept the 50 ms debounce passed to it by gpio_keys.c as a valid value and then setting that breaks the wake from suspend?That's right.
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Also comparing the GPIO register in Windows (where things work) Windows never programs a debounce.So maybe the windows ACPI0011 driver always uses a software- debounce for the buttons? Windows not debouncing the mechanical switches at all seems unlikely. I think the best way to fix this might be to add a no-hw-debounce flag to the data passed from soc_button_array.c to gpio_keys.c and have gpio_keys.c not call gpiod_set_debounce() when the no-hw-debounce flag is set. I've checked and both on Bay Trail and Cherry Trail devices where soc_button_array is used a lot hw-debouncing is already unused. pinctrl-baytrail.c does not accept 50 ms as a valid value and pinctrl-cherryview.c does not support hw debounce at all.That sounds a like a generally good direction to me.
Thinking a bit more of this, perhaps the HW debounce support flag should be per-GPIO-descriptor thingy. In such cases we don't need to distinguish the platforms, the GPIO ACPI lib may simply set that flag based on 0 read from the ACPI tables. It will also give a clue to any driver that uses GPIOs (not only gpio-keys). -- With Best Regards, Andy Shevchenko