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-rw-r--r--drivers/hid/hid-core.c11
-rw-r--r--drivers/hid/hid-input.c13
2 files changed, 10 insertions, 14 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
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 8741d953dcc8..d97f2323af57 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -192,6 +192,7 @@ static int hidinput_setkeycode(struct input_dev *dev,
return -EINVAL;
}
+
/**
* hidinput_calc_abs_res - calculate an absolute axis resolution
* @field: the HID report field to calculate resolution for
@@ -234,23 +235,17 @@ __s32 hidinput_calc_abs_res(const struct hid_field *field, __u16 code)
case ABS_MT_TOOL_Y:
case ABS_MT_TOUCH_MAJOR:
case ABS_MT_TOUCH_MINOR:
- if (field->unit & 0xffffff00) /* Not a length */
- return 0;
- unit_exponent += hid_snto32(field->unit >> 4, 4) - 1;
- switch (field->unit & 0xf) {
- case 0x1: /* If centimeters */
+ if (field->unit == 0x11) { /* If centimeters */
/* Convert to millimeters */
unit_exponent += 1;
- break;
- case 0x3: /* If inches */
+ } else if (field->unit == 0x13) { /* If inches */
/* Convert to millimeters */
prev = physical_extents;
physical_extents *= 254;
if (physical_extents < prev)
return 0;
unit_exponent -= 1;
- break;
- default:
+ } else {
return 0;
}
break;