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HID: core: de-duplicate some code in hid_input_field() 

I had to go twice through the history to get a grasp at this code.
De-duplicate the various tests in one common helper to make it
more explicit.

Note that the `HID_UP_KEYBOARD + 1` condition is tested through
https://gitlab.freedesktop.org/libevdev/hid-tools/-/merge_requests/121

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Reviewed-by: Ping Cheng <ping.cheng@wacom.com>
Acked-by: Peter Hutterer <peter.hutterer@who-t.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Benjamin Tissoires 2022-02-03 15:32:16 +01:00 committed by Jiri Kosina
parent 1c1813a743
commit 74acc277b6
1 changed files with 38 additions and 14 deletions
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52
drivers/hid/hid-core.c
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@ -1525,6 +1525,24 @@ static void hid_process_event(struct hid_device *hid, struct hid_field *field,
hid->hiddev_hid_event(hid, field, usage, value);
}
/*
* Checks if the given value is valid within this field
*/
static inline int hid_array_value_is_valid(struct hid_field *field,
__s32 value)
{
__s32 min = field->logical_minimum;
/*
* Value needs to be between logical min and max, and
* (value - min) is used as an index in the usage array.
* This array is of size field->maxusage
*/
return value >= min &&
value <= field->logical_maximum &&
value - min < field->maxusage;
}
/*
* Analyse a received field, and fetch the data from it. The field
* content is stored for next report processing (we do differential
@ -1539,7 +1557,6 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
unsigned offset = field->report_offset;
unsigned size = field->report_size;
__s32 min = field->logical_minimum;
__s32 max = field->logical_maximum;
__s32 *value;
value = field->new_value;
@ -1554,8 +1571,7 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
/* Ignore report if ErrorRollOver */
if (!(field->flags & HID_MAIN_ITEM_VARIABLE) &&
value[n] >= min && value[n] <= max &&
value[n] - min < field->maxusage &&
hid_array_value_is_valid(field, value[n]) &&
field->usage[value[n] - min].hid == HID_UP_KEYBOARD + 1)
return;
}
@ -1563,21 +1579,29 @@ static void hid_input_field(struct hid_device *hid, struct hid_field *field,
for (n = 0; n < count; n++) {
if (HID_MAIN_ITEM_VARIABLE & field->flags) {
hid_process_event(hid, field, &field->usage[n], value[n], interrupt);
hid_process_event(hid,
field,
&field->usage[n],
value[n],
interrupt);
continue;
}
if (field->value[n] >= min && field->value[n] <= max
&& field->value[n] - min < field->maxusage
&& field->usage[field->value[n] - min].hid
&& search(value, field->value[n], count))
hid_process_event(hid, field, &field->usage[field->value[n] - min], 0, interrupt);
if (hid_array_value_is_valid(field, field->value[n]) &&
search(value, field->value[n], count))
hid_process_event(hid,
field,
&field->usage[field->value[n] - min],
0,
interrupt);
if (value[n] >= min && value[n] <= max
&& value[n] - min < field->maxusage
&& field->usage[value[n] - min].hid
&& search(field->value, value[n], count))
hid_process_event(hid, field, &field->usage[value[n] - min], 1, interrupt);
if (hid_array_value_is_valid(field, value[n]) &&
search(field->value, value[n], count))
hid_process_event(hid,
field,
&field->usage[value[n] - min],
1,
interrupt);
}
memcpy(field->value, value, count * sizeof(__s32));