From e2b95b27196cc90f37016d79432fb2af3f9c9291 Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Wed, 21 Nov 2018 16:27:06 +0100 Subject: [PATCH] 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 Acked-by: Harry Cutts Acked-by: Dmitry Torokhov Acked-by: Jiri Kosina --- drivers/hid/hid-input.c | 43 +++++++++++++++++++++-------------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/hid/hid-input.c b/drivers/hid/hid-input.c index 44ea8e7c71a9..28ee2ed88a1a 100644 --- a/drivers/hid/hid-input.c +++ b/drivers/hid/hid-input.c @@ -1858,30 +1858,31 @@ EXPORT_SYMBOL_GPL(hidinput_disconnect); 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); -- 2.45.2