diff options
| -rw-r--r-- | drivers/hid/hid-input.c | 43 |
1 files changed, 21 insertions, 22 deletions
diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 567c3bf64515..a2f74e6adc70 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1855,31 +1855,30 @@ EXPORT_SYMBOL_GPL(hidinput_disconnect); void hid_scroll_counter_handle_scroll(struct hid_scroll_counter *counter, int hi_res_value) { - 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; + int low_res_value, remainder, multiplier; input_report_rel(counter->dev, REL_WHEEL_HI_RES, hi_res_value * counter->microns_per_hi_res_unit); - 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; - } + /* + * 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); } EXPORT_SYMBOL_GPL(hid_scroll_counter_handle_scroll); |