> -----Original Message-----
> From: Hans de Goede <hdegoede@xxxxxxxxxx>
> Sent: Sunday, October 25, 2020 2:46 AM
> To: Rafael J . Wysocki <rjw@xxxxxxxxxxxxx>; Len Brown <lenb@xxxxxxxxxx>;
> Moore, Robert <robert.moore@xxxxxxxxx>; Kaneda, Erik
> <erik.kaneda@xxxxxxxxx>
> Cc: Hans de Goede <hdegoede@xxxxxxxxxx>; linux-acpi@xxxxxxxxxxxxxxx;
> devel@xxxxxxxxxx
> Subject: [PATCH] ACPICA: Also handle "orphan" _REG methods for GPIO
> OpRegions
>
> Before this commit acpi_ev_execute_reg_methods() had special handling
> to handle "orphan" (no matching OpRegion declared) _REG methods for EC
> nodes.
>
> On Intel Cherry Trail devices there are 2 possible ACPI OpRegions for
> accessing GPIOs. The standard GeneralPurposeIo OpRegion and the Cherry
> Trail specific UserDefined 0x9X OpRegions.
>
> Having 2 different types of OpRegions leads to potential issues with
> checks for OpRegion availability, or in other words checks if _REG has
> been called for the OpRegion which the ACPI code wants to use.
>
> Except for the "orphan" EC handling, ACPICA core does not call _REG on
> an ACPI node which does not define an OpRegion matching the type being
> registered; and the reference design DSDT, from which most Cherry Trail
> DSDTs are derived, does not define GeneralPurposeIo, nor
> UserDefined(0x93)
> OpRegions for the GPO2 (UID 3) device, because no pins were assigned ACPI
> controlled functions in the reference design.
>
> Together this leads to the perfect storm, at least on the Cherry Trail
> based Medion Akayo E1239T. This design does use a GPO2 pin from its ACPI
> code and has added the Cherry Trail specific UserDefined(0x93) opregion
> to its GPO2 ACPI node to access this pin.
>
> But it uses a has _REG been called availability check for the standard
> GeneralPurposeIo OpRegion. This clearly is a bug in the DSDT, but this
> does work under Windows. This issue leads to the intel_vbtn driver
> reporting the device always being in tablet-mode at boot, even if it
> is in laptop mode. Which in turn causes userspace to ignore touchpad
> events. So iow this issues causes the touchpad to not work at boot.
>
> This commit fixes this by extending the "orphan" _REG method handling
> to also apply to GPIO address-space handlers.
>
> Note it seems that Windows always calls "orphan" _REG methods so me
> may want to consider dropping the space-id check and always do
> "orphan" _REG method handling.
>
> Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx>
> ---
> drivers/acpi/acpica/evregion.c | 54 +++++++++++++++++-----------------
> 1 file changed, 27 insertions(+), 27 deletions(-)
>
> diff --git a/drivers/acpi/acpica/evregion.c b/drivers/acpi/acpica/evregion.c
> index 738d4b231f34..21ff341e34a4 100644
> --- a/drivers/acpi/acpica/evregion.c
> +++ b/drivers/acpi/acpica/evregion.c
> @@ -21,7 +21,8 @@ extern u8 acpi_gbl_default_address_spaces[];
> /* Local prototypes */
>
> static void
> -acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node
> *ec_device_node);
> +acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node
> *device_node,
> + acpi_adr_space_type space_id);
>
> static acpi_status
> acpi_ev_reg_run(acpi_handle obj_handle,
> @@ -684,10 +685,12 @@ acpi_ev_execute_reg_methods(struct
> acpi_namespace_node *node,
> ACPI_NS_WALK_UNLOCK,
> acpi_ev_reg_run, NULL,
> &info, NULL);
>
> - /* Special case for EC: handle "orphan" _REG methods with no region
> */
> -
> - if (space_id == ACPI_ADR_SPACE_EC) {
> - acpi_ev_orphan_ec_reg_method(node);
> + /*
> + * Special case for EC and GPIO: handle "orphan" _REG methods with
> + * no region.
> + */
> + if (space_id == ACPI_ADR_SPACE_EC || space_id ==
> ACPI_ADR_SPACE_GPIO) {
> + acpi_ev_execute_orphan_reg_method(node, space_id);
> }
>
> ACPI_DEBUG_PRINT_RAW((ACPI_DB_NAMES,
> @@ -760,31 +763,28 @@ acpi_ev_reg_run(acpi_handle obj_handle,
>
>
> /**********************************************************
> *********************
> *
> - * FUNCTION: acpi_ev_orphan_ec_reg_method
> + * FUNCTION: acpi_ev_execute_orphan_reg_method
> *
> - * PARAMETERS: ec_device_node - Namespace node for an EC device
> + * PARAMETERS: device_node - Namespace node for an ACPI device
> + * space_id - The address space ID
> *
> * RETURN: None
> *
> - * DESCRIPTION: Execute an "orphan" _REG method that appears under the
> EC
> + * DESCRIPTION: Execute an "orphan" _REG method that appears under an
> ACPI
> * device. This is a _REG method that has no corresponding region
> - * within the EC device scope. The orphan _REG method appears to
> - * have been enabled by the description of the ECDT in the ACPI
> - * specification: "The availability of the region space can be
> - * detected by providing a _REG method object underneath the
> - * Embedded Controller device."
> - *
> - * To quickly access the EC device, we use the ec_device_node used
> - * during EC handler installation. Otherwise, we would need to
> - * perform a time consuming namespace walk, executing _HID
> - * methods to find the EC device.
> + * within the device's scope. ACPI tables depending on these
> + * "orphan" _REG methods have been seen for both EC and GPIO
> + * Operation Regions. Presumably the Windows ACPI implementation
> + * always calls the _REG method independent of the presence of
> + * an actual Operation Region with the correct address space ID.
> *
> * MUTEX: Assumes the namespace is locked
> *
>
> **********************************************************
> ********************/
>
> static void
> -acpi_ev_orphan_ec_reg_method(struct acpi_namespace_node
> *ec_device_node)
> +acpi_ev_execute_orphan_reg_method(struct acpi_namespace_node
> *device_node,
> + acpi_adr_space_type space_id)
> {
> acpi_handle reg_method;
> struct acpi_namespace_node *next_node;
> @@ -792,9 +792,9 @@ acpi_ev_orphan_ec_reg_method(struct
> acpi_namespace_node *ec_device_node)
> struct acpi_object_list args;
> union acpi_object objects[2];
>
> - ACPI_FUNCTION_TRACE(ev_orphan_ec_reg_method);
> + ACPI_FUNCTION_TRACE(ev_execute_orphan_reg_method);
>
> - if (!ec_device_node) {
> + if (!device_node) {
> return_VOID;
> }
>
> @@ -804,7 +804,7 @@ acpi_ev_orphan_ec_reg_method(struct
> acpi_namespace_node *ec_device_node)
>
> /* Get a handle to a _REG method immediately under the EC device
> */
>
> - status = acpi_get_handle(ec_device_node, METHOD_NAME__REG,
> ®_method);
> + status = acpi_get_handle(device_node, METHOD_NAME__REG,
> ®_method);
> if (ACPI_FAILURE(status)) {
> goto exit; /* There is no _REG method present */
> }
> @@ -816,23 +816,23 @@ acpi_ev_orphan_ec_reg_method(struct
> acpi_namespace_node *ec_device_node)
> * with other space IDs to be present; but the code below will then
> * execute the _REG method with the embedded_control space_ID
> argument.
> */
> - next_node = acpi_ns_get_next_node(ec_device_node, NULL);
> + next_node = acpi_ns_get_next_node(device_node, NULL);
> while (next_node) {
> if ((next_node->type == ACPI_TYPE_REGION) &&
> (next_node->object) &&
> - (next_node->object->region.space_id ==
> ACPI_ADR_SPACE_EC)) {
> + (next_node->object->region.space_id == space_id)) {
> goto exit; /* Do not execute the _REG */
> }
>
> - next_node = acpi_ns_get_next_node(ec_device_node,
> next_node);
> + next_node = acpi_ns_get_next_node(device_node,
> next_node);
> }
>
> - /* Evaluate the _REG(embedded_control,Connect) method */
> + /* Evaluate the _REG(space_id, Connect) method */
>
> args.count = 2;
> args.pointer = objects;
> objects[0].type = ACPI_TYPE_INTEGER;
> - objects[0].integer.value = ACPI_ADR_SPACE_EC;
> + objects[0].integer.value = space_id;
> objects[1].type = ACPI_TYPE_INTEGER;
> objects[1].integer.value = ACPI_REG_CONNECT;
>
> --
> 2.28.0
This looks good to me. Bob, any thoughts?
Erik
