Messages in this thread | | | Date | Thu, 28 Aug 2014 13:19:48 +0200 | From | Tomasz Nowicki <> | Subject | Re: [PATCH] ACPI: Add GPIO-signaled event emulator. |
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On 26.08.2014 00:39, Rafael J. Wysocki wrote: > On Thursday, August 21, 2014 04:39:46 PM Tomasz Nowicki wrote: >> Hi Mika, >> >> On 21.08.2014 12:45, Mika Westerberg wrote: >>> On Wed, Aug 20, 2014 at 04:58:20PM +0200, Tomasz Nowicki wrote: > > [cut] > >>>> + >>>> +static int gpio_evt_trigger(void *data, u64 val) >>>> +{ >>>> + struct gpio_pin_data *pin_data = (struct gpio_pin_data *)data; >>>> + int pin = pin_data->pin; >>>> + >>>> + if (ACPI_FAILURE(acpi_execute_simple_method(pin_data->handle, NULL, >>>> + pin <= 255 ? 0 : pin))) >>>> + pr_err(PREFIX "evaluating event method failed\n"); >>> >>> acpi_execute_simple_method() passes one argument to the method. You >>> can't use it with _Lxx or _Exx which don't expect any arguments. >>> Otherwise you get this: >>> >>> [ 122.258191] ACPI: \_SB_.GPO2._E12: Excess arguments - Caller passed 1, method requires 0 (20140724/nsarguments-263) >> Right, I will fix it. > > OK, so here's my concern. > > If AML does any kind of tracking of state in _Exx/_Lxx, you'll likely totally > confuse it by calling those things at random. > > I'm not sure I'm seeing a compelling reason to put this thing into the tree > for this reason.
Yes you are right, but this emulator is only for debugging/development purposes and goes with clear statement "DANGER to use on production kernel", like APEI error injection feature.
IMO, this emulator would help with: 1. testing and developing AML methods 2. working on ACPI subsystems that need GPIO-signaled events without GPIO h/w
Regards, Tomasz
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