From: Philipp Zabel <philipp.zabel@gmail.com>
Date: Mon, 14 Jan 2019 07:19:22 +0000 (+0100)
Subject: HID: core: simplify active collection tracking
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=1950f462916edc9581168ca8d5882a8101e8bbcf;p=linux.git

HID: core: simplify active collection tracking

Manually tracking an active collection to set collection parents is not
necessary, we just have to look one step back into the collection stack
to find the correct parent.

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
---

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f9093dedf647c..9993b692598fb 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -173,8 +173,8 @@ static int open_collection(struct hid_parser *parser, unsigned type)
 	collection->type = type;
 	collection->usage = usage;
 	collection->level = parser->collection_stack_ptr - 1;
-	collection->parent_idx = parser->active_collection_idx;
-	parser->active_collection_idx = collection_index;
+	collection->parent_idx = (collection->level == 0) ? -1 :
+		parser->collection_stack[collection->level - 1];
 
 	if (type == HID_COLLECTION_APPLICATION)
 		parser->device->maxapplication++;
@@ -193,13 +193,6 @@ static int close_collection(struct hid_parser *parser)
 		return -EINVAL;
 	}
 	parser->collection_stack_ptr--;
-	if (parser->active_collection_idx != -1) {
-		struct hid_device *device = parser->device;
-		struct hid_collection *c;
-
-		c = &device->collection[parser->active_collection_idx];
-		parser->active_collection_idx = c->parent_idx;
-	}
 	return 0;
 }
 
@@ -825,7 +818,6 @@ static int hid_scan_report(struct hid_device *hid)
 		return -ENOMEM;
 
 	parser->device = hid;
-	parser->active_collection_idx = -1;
 	hid->group = HID_GROUP_GENERIC;
 
 	/*
@@ -1179,7 +1171,6 @@ int hid_open_report(struct hid_device *device)
 	}
 
 	parser->device = device;
-	parser->active_collection_idx = -1;
 
 	end = start + size;
 
diff --git a/include/linux/hid.h b/include/linux/hid.h
index 992bbb7196df4..f9707d1dcb584 100644
--- a/include/linux/hid.h
+++ b/include/linux/hid.h
@@ -658,7 +658,6 @@ struct hid_parser {
 	unsigned int         *collection_stack;
 	unsigned int          collection_stack_ptr;
 	unsigned int          collection_stack_size;
-	int                   active_collection_idx; /* device->collection */
 	struct hid_device    *device;
 	unsigned int          scan_flags;
 };