[PATCH 2/7] Input: libps2 - remove special handling of ACK for command byte

From: Dmitry Torokhov
Date: Thu May 11 2023 - 14:53:13 EST


When getting unexpected data while waiting for an acknowledgement it does
not matter what command phase is currently executed, and ps2_handle_ack()
should indicate that no further processing is needed for the received data
byte. Remove PS2_FLAG_ACK_CMD and associated handling.

Note that while it is possible to make ps2_handle_ack (and
ps2_handle_repsonse) return void, it will be done when the code will be
converted to common PS/2 interrupt handler later.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
---
drivers/input/serio/libps2.c | 9 ++-------
include/linux/libps2.h | 1 -
2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 764990723847..399cda0d34f5 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -253,9 +253,6 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
for (i = 0; i < receive; i++)
ps2dev->cmdbuf[(receive - 1) - i] = param[i];

- /* Signal that we are sending the command byte */
- ps2dev->flags |= PS2_FLAG_ACK_CMD;
-
/*
* Some devices (Synaptics) peform the reset before
* ACKing the reset command, and so it can take a long
@@ -267,9 +264,7 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
if (rc)
goto out_reset_flags;

- /* Now we are sending command parameters, if any */
- ps2dev->flags &= ~PS2_FLAG_ACK_CMD;
-
+ /* Send command parameters, if any. */
for (i = 0; i < send; i++) {
rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2);
if (rc)
@@ -436,7 +431,7 @@ bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data)
*/
dev_dbg(&ps2dev->serio->dev, "unexpected %#02x\n", data);
ps2dev->flags &= ~PS2_FLAG_WAITID;
- return ps2dev->flags & PS2_FLAG_ACK_CMD;
+ return true;
}

if (!ps2dev->nak) {
diff --git a/include/linux/libps2.h b/include/linux/libps2.h
index 53f7e4d0f4b7..193dd53ad18b 100644
--- a/include/linux/libps2.h
+++ b/include/linux/libps2.h
@@ -28,7 +28,6 @@
#define PS2_FLAG_CMD1 BIT(2) /* Waiting for the first byte of command response */
#define PS2_FLAG_WAITID BIT(3) /* Command executing is GET ID */
#define PS2_FLAG_NAK BIT(4) /* Last transmission was NAKed */
-#define PS2_FLAG_ACK_CMD BIT(5) /* Waiting to ACK the command (first) byte */

struct ps2dev {
struct serio *serio;
--
2.40.1.606.ga4b1b128d6-goog