Re: [PATCH 2/2] gpiolib: acpi: Add honor_wakeup module-option + quirk mechanism

[Hans de Goede <hdegoede@redhat.com>]

Hi,

On 25-11-2019 10:25, Andy Shevchenko wrote:
> On Fri, Nov 22, 2019 at 08:23:34PM +0100, Hans de Goede wrote:
>> On some laptops enabling wakeup on the GPIO interrupts used for ACPI _AEI
>> event handling causes spurious wakeups.
>>
>> This commit adds a new honor_wakeup option, defaulting to true (our current
>> behavior), which can be used to disable wakeup on troublesome hardware
>> to avoid these spurious wakeups.
>>
>> This is a workaround for an architectural problem with s2idle under Linux
>> where we do not have any mechanism to immediately go back to sleep after
>> wakeup events, other then for embedded-controller events using the standard
>> ACPI EC interface, for details see:
>> https://lore.kernel.org/linux-acpi/61450f9b-cbc6-0c09-8b3a-aff6bf9a0b3c@redhat.com/
>>
>> One series of laptops which is not able to suspend without this workaround
>> is the HP x2 10 Cherry Trail models, this commit adds a DMI based quirk
>> which makes sets honor_wakeup to false on these models.
> 
> I'm not against this approach (yeah, it seems we will always have a stream of
> quirks for BIOS enabled platforms, especially cheapest ones), though last word
> is by Rafael.
> 
> Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

Thanks.

> One nit below, though.
> 
>>
>> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
>> ---
>>   drivers/gpio/gpiolib-acpi.c | 33 ++++++++++++++++++++++++++++++++-
>>   1 file changed, 32 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/gpio/gpiolib-acpi.c b/drivers/gpio/gpiolib-acpi.c
>> index 2b47d906d536..9ce9b449ac4b 100644
>> --- a/drivers/gpio/gpiolib-acpi.c
>> +++ b/drivers/gpio/gpiolib-acpi.c
>> @@ -22,12 +22,18 @@
>>   #include "gpiolib-acpi.h"
>>   
>>   #define QUIRK_NO_EDGE_EVENTS_ON_BOOT		0x01l
>> +#define QUIRK_NO_WAKEUP				0x02l
>>   
>>   static int run_edge_events_on_boot = -1;
>>   module_param(run_edge_events_on_boot, int, 0444);
>>   MODULE_PARM_DESC(run_edge_events_on_boot,
>>   		 "Run edge _AEI event-handlers at boot: 0=no, 1=yes, -1=auto");
>>   
>> +static int honor_wakeup = -1;
>> +module_param(honor_wakeup, int, 0444);
>> +MODULE_PARM_DESC(honor_wakeup,
>> +		 "Honor the ACPI wake-capable flag: 0=no, 1=yes, -1=auto");
>> +
>>   /**
>>    * struct acpi_gpio_event - ACPI GPIO event handler data
>>    *
>> @@ -283,7 +289,8 @@ static acpi_status acpi_gpiochip_alloc_event(struct acpi_resource *ares,
>>   	event->handle = evt_handle;
>>   	event->handler = handler;
>>   	event->irq = irq;
>> -	event->irq_is_wake = agpio->wake_capable == ACPI_WAKE_CAPABLE;
> 
>> +	if (honor_wakeup)
>> +		event->irq_is_wake = agpio->wake_capable == ACPI_WAKE_CAPABLE;
> 
> Perhaps:
> 
> 	event->irq_is_wake = honor_wakeup && agpio->wake_capable == ACPI_WAKE_CAPABLE;

Yes that is better, I also noticed some typos in the comment explaining why the
quirk is necessary, I will submit a v2 fixing both.

Regards,

Hans



> (I don't care about 80 limit here)
> 
>>   	event->pin = pin;
>>   	event->desc = desc;
>>   
>> @@ -1337,6 +1344,23 @@ static const struct dmi_system_id gpiolib_acpi_quirks[] = {
>>   		},
>>   		.driver_data = (void *)QUIRK_NO_EDGE_EVENTS_ON_BOOT,
>>   	},
>> +	{
>> +		/*
>> +		 * Various HP X2 10 Cherry Trail models use external
>> +		 * embedded-controller connected via I2C + a ACPI GPIO
>> +		 * event handler. The embedded controller generates various
>> +		 * spurious wakeup events when suspended. So disable wakeup
>> +		 * for its handler (it used the only ACPI GPIO event handler).
>> +		 * This breaks wakeup when opening the lid, the user needs
>> +		 * to press the power-button to wakeup the system. The
>> +		 * alternative is suspend simply not working, which is worse.
>> +		 */
>> +		.matches = {
>> +			DMI_MATCH(DMI_SYS_VENDOR, "HP"),
>> +			DMI_MATCH(DMI_PRODUCT_NAME, "HP x2 Detachable 10-p0XX"),
>> +		},
>> +		.driver_data = (void *)QUIRK_NO_WAKEUP,
>> +	},
>>   	{} /* Terminating entry */
>>   };
>>   
>> @@ -1356,6 +1380,13 @@ static int acpi_gpio_setup_params(void)
>>   			run_edge_events_on_boot = 1;
>>   	}
>>   
>> +	if (honor_wakeup < 0) {
>> +		if (quirks & QUIRK_NO_WAKEUP)
>> +			honor_wakeup = 0;
>> +		else
>> +			honor_wakeup = 1;
>> +	}
>> +
>>   	return 0;
>>   }
>>   
>> -- 
>> 2.23.0
>>
>