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@xxxxxxxxx>
Tested-by: Igor Gnatenko <i.gnatenko.brain@xxxxxxxxx>
Acked-by: Henrique de Moraes Holschuh <hmh@xxxxxxxxxx>
---
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);
--
1.8.4.12.g2ea3df6
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