[PATCH] Revert "Input: matrix_keypad - force switch rows to input mode"

[Alexander Kochetkov]

This reverts commit 01c84b03d80aab9f04c4e3e1f9085f4202ff7c29.

The commit makes every scan call gpiod_direction_input() on the row
GPIOs. On pin controllers where GPIO input and interrupt are separate
pinmux functions this switches the row pins out of interrupt mode, and
enable_row_irqs() does not switch them back: it only unmasks the
interrupts. Row interrupts then never arrive and the keypad stops
working. Seen with a matrix keypad on an Allwinner A64 board (PINE
A64-LTS); it works again with the commit reverted.

The workaround is not needed on Ingenic either: the author of the
reverted commit re-tested all available JZ47xx SoCs and they all report
the live pin state in interrupt mode, see the thread in Link.

Fixes: 01c84b03d80a ("Input: matrix_keypad - force switch rows to input mode")
Link: https://lore.kernel.org/all/4130C026-2A83-408B-836A-ECA044491C47@xxxxxxxxx/
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Alexander Kochetkov <al.kochet@xxxxxxxxx>
---
The same three-line removal has been in use on Allwinner A64 hardware on
top of v6.12.33; this version is rebased onto v7.3-rc5 and build-tested
(arm64, CONFIG_KEYBOARD_MATRIX=m).

Siarhei, Paul: you both agreed to the revert in the thread above, please
reply with your Acked-by/Tested-by if you would like it recorded.

 drivers/input/keyboard/matrix_keypad.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/input/keyboard/matrix_keypad.c b/drivers/input/keyboard/matrix_keypad.c
index 8863b741d1a3..cda2888b2e56 100644
--- a/drivers/input/keyboard/matrix_keypad.c
+++ b/drivers/input/keyboard/matrix_keypad.c
@@ -134,9 +134,6 @@ static void matrix_keypad_scan(struct work_struct *work)
 
 	memset(new_state, 0, sizeof(new_state));
 
-	for (row = 0; row < keypad->num_row_gpios; row++)
-		gpiod_direction_input(keypad->row_gpios[row]);
-
 	/* assert each column and read the row status out */
 	for (col = 0; col < keypad->num_col_gpios; col++) {
 

base-commit: 72d3fcf802c45d00b300f25b848a93c3a2bd7c7e
-- 
2.43.0