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From:   Joao Moreno <mail@joaomoreno.com>
Cc:     Joao Moreno <mail@joaomoreno.com>, Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] HID: apple: Fix stuck function keys when using FN
Date:   Mon, 10 Jun 2019 23:31:06 +0200
Message-Id: <20190610213106.19342-1-mail@joaomoreno.com>
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This fixes an issue in which key down events for function keys would be
repeatedly emitted even after the user has raised the physical key. For
example, the driver fails to emit the F5 key up event when going through
the following steps:
- fnmode=1: hold FN, hold F5, release FN, release F5
- fnmode=2: hold F5, hold FN, release F5, release FN

The repeated F5 key down events can be easily verified using xev.

Signed-off-by: Joao Moreno <mail@joaomoreno.com>
---
 drivers/hid/hid-apple.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/drivers/hid/hid-apple.c b/drivers/hid/hid-apple.c
index 1cb41992aaa1..81867a6fa047 100644
--- a/drivers/hid/hid-apple.c
+++ b/drivers/hid/hid-apple.c
@@ -205,20 +205,21 @@ static int hidinput_apple_event(struct hid_device *hid, struct input_dev *input,
 		trans = apple_find_translation (table, usage->code);
 
 		if (trans) {
-			if (test_bit(usage->code, asc->pressed_fn))
-				do_translate = 1;
-			else if (trans->flags & APPLE_FLAG_FKEY)
-				do_translate = (fnmode == 2 && asc->fn_on) ||
-					(fnmode == 1 && !asc->fn_on);
+			int fn_on = value ? asc->fn_on :
+				test_bit(usage->code, asc->pressed_fn);
+
+			if (!value)
+				clear_bit(usage->code, asc->pressed_fn);
+			else if (asc->fn_on)
+				set_bit(usage->code, asc->pressed_fn);
+
+			if (trans->flags & APPLE_FLAG_FKEY)
+				do_translate = (fnmode == 2 && fn_on) ||
+					(fnmode == 1 && !fn_on);
 			else
 				do_translate = asc->fn_on;
 
 			if (do_translate) {
-				if (value)
-					set_bit(usage->code, asc->pressed_fn);
-				else
-					clear_bit(usage->code, asc->pressed_fn);
-
 				input_event(input, usage->type, trans->to,
 						value);
 
-- 
2.19.1