The tpacpi_acpi_handle_locate function makes use of acpi_get_devices to locate handle for ACPI video by HID, the problem is, ACPI video node doesn't really have HID defined(i.e. no _HID control method is defined for video device), so.. that function would fail. This can be solved by enhancing the callback function for acpi_get_devices, where we can use acpi_device_hid function to check if the ACPI node corresponds to a video controller.
In addition to that, the _BCL control method only exists under a video output device node, not a video controller device node. So to evaluate _BCL, we need the handle of a video output device node, which is child of the located video controller node from tpacpi_acpi_handle_locate.
The two fix are necessary for some Thinkpad models to emit notification on backlight hotkey press as a result of evaluation of _BCL.
Signed-off-by: Aaron Lu aaron.lu@intel.com Tested-by: Igor Gnatenko i.gnatenko.brain@gmail.com Acked-by: Henrique de Moraes Holschuh hmh@hmh.eng.br --- drivers/platform/x86/thinkpad_acpi.c | 31 ++++++++++++++++++++++++------- 1 file changed, 24 insertions(+), 7 deletions(-)
diff --git a/drivers/platform/x86/thinkpad_acpi.c b/drivers/platform/x86/thinkpad_acpi.c index 03ca6c1..170f278 100644 --- a/drivers/platform/x86/thinkpad_acpi.c +++ b/drivers/platform/x86/thinkpad_acpi.c @@ -700,6 +700,14 @@ static void __init drv_acpi_handle_init(const char *name, static acpi_status __init tpacpi_acpi_handle_locate_callback(acpi_handle handle, u32 level, void *context, void **return_value) { + struct acpi_device *dev; + if (!strcmp(context, "video")) { + if (acpi_bus_get_device(handle, &dev)) + return AE_OK; + if (strcmp(ACPI_VIDEO_HID, acpi_device_hid(dev))) + return AE_OK; + } + *(acpi_handle *)return_value = handle;
return AE_CTRL_TERMINATE; @@ -712,10 +720,10 @@ static void __init tpacpi_acpi_handle_locate(const char *name, acpi_status status; acpi_handle device_found;
- BUG_ON(!name || !hid || !handle); + BUG_ON(!name || !handle); vdbg_printk(TPACPI_DBG_INIT, "trying to locate ACPI handle for %s, using HID %s\n", - name, hid); + name, hid ? hid : "NULL");
memset(&device_found, 0, sizeof(device_found)); status = acpi_get_devices(hid, tpacpi_acpi_handle_locate_callback, @@ -6090,19 +6098,28 @@ static int __init tpacpi_query_bcl_levels(acpi_handle handle) { struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; union acpi_object *obj; + struct acpi_device *device, *child; int rc;
- if (ACPI_SUCCESS(acpi_evaluate_object(handle, "_BCL", NULL, &buffer))) { + if (acpi_bus_get_device(handle, &device)) + return 0; + + rc = 0; + list_for_each_entry(child, &device->children, node) { + acpi_status status = acpi_evaluate_object(child->handle, "_BCL", + NULL, &buffer); + if (ACPI_FAILURE(status)) + continue; + obj = (union acpi_object *)buffer.pointer; if (!obj || (obj->type != ACPI_TYPE_PACKAGE)) { pr_err("Unknown _BCL data, please report this to %s\n", - TPACPI_MAIL); + TPACPI_MAIL); rc = 0; } else { rc = obj->package.count; } - } else { - return 0; + break; }
kfree(buffer.pointer); @@ -6118,7 +6135,7 @@ static unsigned int __init tpacpi_check_std_acpi_brightness_support(void) acpi_handle video_device; int bcl_levels = 0;
- tpacpi_acpi_handle_locate("video", ACPI_VIDEO_HID, &video_device); + tpacpi_acpi_handle_locate("video", NULL, &video_device); if (video_device) bcl_levels = tpacpi_query_bcl_levels(video_device);