[PATCH 3.13.y-ckt 10/97] HID: fix hid_ignore_special_drivers module parameter

From: Kamal Mostafa
Date: Mon Apr 04 2016 - 19:52:23 EST


3.13.11-ckt38 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>

commit 4392bf333388cabdad5afe5b1500002d7b9c318e upstream.

hid_ignore_special_drivers works fine until hid_scan_report autodetects and
reassign devices (for hid-multitouch, hid-microsoft and hid-rmi).

Simplify the handling of the parameter: if it is there, use hid-generic, no
matter what, and if not, scan the device or rely on the hid_have_special_driver
table.

This was detected while trying to disable hid-multitouch on a Surface Pro cover
which prevented to use the keyboard.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@xxxxxxxxxx>
Signed-off-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/hid/hid-core.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index 1d247ea..8a0cfa0 100644
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2453,9 +2453,10 @@ int hid_add_device(struct hid_device *hdev)
/*
* Scan generic devices for group information
*/
- if (hid_ignore_special_drivers ||
- (!hdev->group &&
- !hid_match_id(hdev, hid_have_special_driver))) {
+ if (hid_ignore_special_drivers) {
+ hdev->group = HID_GROUP_GENERIC;
+ } else if (!hdev->group &&
+ !hid_match_id(hdev, hid_have_special_driver)) {
ret = hid_scan_report(hdev);
if (ret)
hid_warn(hdev, "bad device descriptor (%d)\n", ret);
--
2.7.4