diff options
Diffstat (limited to 'drivers/hid/hid-core.c')
| -rw-r--r-- | drivers/hid/hid-core.c | 11 |
1 files changed, 6 insertions, 5 deletions
diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 5a8c01112a23..a9ca93c1192c 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -319,7 +319,7 @@ static s32 item_sdata(struct hid_item *item) static int hid_parser_global(struct hid_parser *parser, struct hid_item *item) { - __u32 raw_value; + __s32 raw_value; switch (item->tag) { case HID_GLOBAL_ITEM_TAG_PUSH: @@ -370,10 +370,11 @@ static int hid_parser_global(struct hid_parser *parser, struct hid_item *item) return 0; case HID_GLOBAL_ITEM_TAG_UNIT_EXPONENT: - /* Units exponent negative numbers are given through a - * two's complement. - * See "6.2.2.7 Global Items" for more information. */ - raw_value = item_udata(item); + /* Many devices provide unit exponent as a two's complement + * nibble due to the common misunderstanding of HID + * specification 1.11, 6.2.2.7 Global Items. Attempt to handle + * both this and the standard encoding. */ + raw_value = item_sdata(item); if (!(raw_value & 0xfffffff0)) parser->global.unit_exponent = hid_snto32(raw_value, 4); else |