HID: fix hid_ignore_special_drivers module parameter

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@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c
index f16155f5b6e28b9d256b950f33327748a835303a..ec791e169f8f7c205e1428bc3887ddd2dece043c 100644 (file)
--- a/drivers/hid/hid-core.c
+++ b/drivers/hid/hid-core.c
@@ -2616,9 +2616,10 @@ 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);