On Fri, Aug 23, 2019 at 11:52:55PM +0200, Hans de Goede wrote:
> Another day; another DSDT bug we need to workaround...
>
> Since commit ca876c7483b6 ("gpiolib-acpi: make sure we trigger edge events
> at least once on boot") we call _AEI edge handlers at boot.
>
> In some rare cases this causes problems. One example of this is the Minix
> Neo Z83-4 mini PC, this device has a clear DSDT bug where it has some copy
> and pasted code for dealing with Micro USB-B connector host/device role
> switching, while the mini PC does not even have a micro-USB connector.
> This code, which should not be there, messes with the DDC data pin from
> the HDMI connector (switching it to GPIO mode) breaking HDMI support.
>
> To avoid problems like this, this commit adds a new
> gpiolib_acpi_run_edge_events_on_boot kernel commandline option which
> can be "on", "off", or "auto" (default).
>
> In auto mode the default is on and a DMI based blacklist is used,
> the initial version of this blacklist contains the Minix Neo Z83-4
> fixing the HDMI being broken on this device.
> +static int gpiolib_acpi_run_edge_events_on_boot = -1;
> +
> +static int __init gpiolib_acpi_run_edge_events_on_boot_setup(char *arg)
> +{
> + if (!strcmp(arg, "on"))
> + gpiolib_acpi_run_edge_events_on_boot = 1;
> + else if (!strcmp(arg, "off"))
> + gpiolib_acpi_run_edge_events_on_boot = 0;
kstrtobool() ?
> + else if (!strcmp(arg, "auto"))
> + gpiolib_acpi_run_edge_events_on_boot = -1;
> +
> + return 1;
> +}
> +
> +__setup("gpiolib_acpi_run_edge_events_on_boot=",
> + gpiolib_acpi_run_edge_events_on_boot_setup);
Can't we use module_param() ?
The resulting option would be 'gpiolib_acpi.foo=...'
> +{
> + if (gpiolib_acpi_run_edge_events_on_boot == -1) {
> + if (dmi_check_system(run_edge_events_on_boot_blacklist))
> + gpiolib_acpi_run_edge_events_on_boot = 0;
> + else
> + gpiolib_acpi_run_edge_events_on_boot = 1;
> + }
Can we run this at an initcall once and use variable instead of calling a
method below?
> + return gpiolib_acpi_run_edge_events_on_boot;
> +}
> +
> static void acpi_gpiochip_request_irq(struct acpi_gpio_chip *acpi_gpio,
> struct acpi_gpio_event *event)
> {
> @@ -170,10 +211,13 @@ static void acpi_gpiochip_request_irq(struct
> acpi_gpio_chip *acpi_gpio,
> event->irq_requested = true;
>
> /* Make sure we trigger the initial state of edge-triggered IRQs */
> - value = gpiod_get_raw_value_cansleep(event->desc);
> - if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
> - ((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0))
> - event->handler(event->irq, event);
> + if (acpi_gpiochip_run_edge_events_on_boot() &&
> + (event->irqflags & (IRQF_TRIGGER_RISING | IRQF_TRIGGER_FALLING))) {
> + value = gpiod_get_raw_value_cansleep(event->desc);
> + if (((event->irqflags & IRQF_TRIGGER_RISING) && value == 1) ||
> + ((event->irqflags & IRQF_TRIGGER_FALLING) && value == 0))
> + event->handler(event->irq, event);
> + }
--
With Best Regards,
Andy Shevchenko
