From b829a1d2648abd0751e9d3505554547faf643425 Mon Sep 17 00:00:00 2001
From: Simon Arlott <70171+nomis@users.noreply.github.com>
Date: Wed, 9 Jun 2021 08:23:21 +0100
Subject: Avoid 8-bit timer overflows in debounce algorithms (#12240)

* Add fast_timer_t that is 16-bit or 32-bit based on architecture

A 16-bit timer will overflow sooner but be faster to compare on AVR.

* Avoid 8-bit timer overflows in debounce algorithms

Count down remaining elapsed time instead of trying to do 8-bit timer
comparisons.

Add a "none" implementation that is automatically used if DEBOUNCE is
0 otherwise it will break the _pk/_pr count down.

* Avoid unnecessary polling of the entire matrix in sym_eager_pk

The matrix only needs to be updated when a debounce timer expires.

* Avoid unnecessary polling of the entire matrix in sym_eager_pr

The matrix only needs to be updated when a debounce timer expires.

The use of the "needed_update" variable is trying to do what
"matrix_need_update" was added to fix but didn't work because it only
applied when all keys finished debouncing.

* Fix sym_defer_g timing inconsistency compared to other debounce algorithms

DEBOUNCE=5 should process the key after 5ms, not 6ms

* Add debounce tests
---
 quantum/debounce.h | 2 ++
 1 file changed, 2 insertions(+)

(limited to 'quantum/debounce.h')

diff --git a/quantum/debounce.h b/quantum/debounce.h
index 9ca05c6824..5043868289 100644
--- a/quantum/debounce.h
+++ b/quantum/debounce.h
@@ -9,3 +9,5 @@ void debounce(matrix_row_t raw[], matrix_row_t cooked[], uint8_t num_rows, bool
 bool debounce_active(void);
 
 void debounce_init(uint8_t num_rows);
+
+void debounce_free(void);
-- 
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