On Apple devices the _CRS method returns an empty resource template, and the resource settings are instead provided by the _DSM method. But commit 33364d63c75d6182fa369cea80315cf1bb0ee38e (serdev: Add ACPI devices by ResourceSource field) changed the search for serdev devices to require valid, non-empty resource template, thereby breaking Apple devices and causing bluetooth devices to not be found.
This expands the check so that if we don't find a valid template, and we're on an Apple machine, then just check for the device being an immediate child of the controller and having a "baud" property.
Cc: stable@vger.kernel.org # 5.5 Signed-off-by: Ronald Tschalär ronald@innovation.ch --- drivers/tty/serdev/core.c | 10 ++++++++++ 1 file changed, 10 insertions(+)
diff --git a/drivers/tty/serdev/core.c b/drivers/tty/serdev/core.c index ce5309d00280..0f64a10ba51f 100644 --- a/drivers/tty/serdev/core.c +++ b/drivers/tty/serdev/core.c @@ -18,6 +18,7 @@ #include <linux/sched.h> #include <linux/serdev.h> #include <linux/slab.h> +#include <linux/platform_data/x86/apple.h>
static bool is_registered; static DEFINE_IDA(ctrl_ida); @@ -630,6 +631,15 @@ static int acpi_serdev_check_resources(struct serdev_controller *ctrl, if (ret) return ret;
+ /* + * Apple machines provide an empty resource template, so on those + * machines just look for immediate children with a "baud" property + * (from the _DSM method) instead. + */ + if (!lookup.controller_handle && x86_apple_machine && + !acpi_dev_get_property(adev, "baud", ACPI_TYPE_BUFFER, NULL)) + acpi_get_parent(adev->handle, &lookup.controller_handle); + /* Make sure controller and ResourceSource handle match */ if (ACPI_HANDLE(ctrl->dev.parent) != lookup.controller_handle) return -ENODEV;