Revert "HID: input: simplify/fix high-res scroll event handling"
This reverts commit 044ee890286153a1aefb40cb8b6659921aecb38b.
It turns out the current API is not that compatible with
some Microsoft mice, so better start again from scratch.
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Acked-by: Harry Cutts <hcutts@chromium.org>
Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Acked-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c
index 44ea8e7..28ee2ed 100644
--- a/drivers/hid/hid-input.c
+++ b/drivers/hid/hid-input.c
@@ -1858,30 +1858,31 @@
void hid_scroll_counter_handle_scroll(struct hid_scroll_counter *counter,
int hi_res_value)
{
- int low_res_value, remainder, multiplier;
+ int low_res_scroll_amount;
+ /* Some wheels will rest 7/8ths of a notch from the previous notch
+ * after slow movement, so we want the threshold for low-res events to
+ * be in the middle of the notches (e.g. after 4/8ths) as opposed to on
+ * the notches themselves (8/8ths).
+ */
+ int threshold = counter->resolution_multiplier / 2;
input_report_rel(counter->dev, REL_WHEEL_HI_RES,
hi_res_value * counter->microns_per_hi_res_unit);
- /*
- * Update the low-res remainder with the high-res value,
- * but reset if the direction has changed.
- */
- remainder = counter->remainder;
- if ((remainder ^ hi_res_value) < 0)
- remainder = 0;
- remainder += hi_res_value;
-
- /*
- * Then just use the resolution multiplier to see if
- * we should send a low-res (aka regular wheel) event.
- */
- multiplier = counter->resolution_multiplier;
- low_res_value = remainder / multiplier;
- remainder -= low_res_value * multiplier;
- counter->remainder = remainder;
-
- if (low_res_value)
- input_report_rel(counter->dev, REL_WHEEL, low_res_value);
+ counter->remainder += hi_res_value;
+ if (abs(counter->remainder) >= threshold) {
+ /* Add (or subtract) 1 because we want to trigger when the wheel
+ * is half-way to the next notch (i.e. scroll 1 notch after a
+ * 1/2 notch movement, 2 notches after a 1 1/2 notch movement,
+ * etc.).
+ */
+ low_res_scroll_amount =
+ counter->remainder / counter->resolution_multiplier
+ + (hi_res_value > 0 ? 1 : -1);
+ input_report_rel(counter->dev, REL_WHEEL,
+ low_res_scroll_amount);
+ counter->remainder -=
+ low_res_scroll_amount * counter->resolution_multiplier;
+ }
}
EXPORT_SYMBOL_GPL(hid_scroll_counter_handle_scroll);
