Revert "Input: libps2 - support retransmission of command data"

This reverts commit b99e1f2a1a3f4158bed9b9e9e97ac46678d8c2ac.

1 files changed, 32 insertions, 71 deletions

diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index f05c407b31f3..82befae4dab0 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -26,63 +26,35 @@ MODULE_AUTHOR("Dmitry Torokhov <dtor@mail.ru>");
 MODULE_DESCRIPTION("PS/2 driver library");
 MODULE_LICENSE("GPL");
 
-static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte,
-			   unsigned int timeout, unsigned int max_attempts)
-	__releases(&ps2dev->serio->lock) __acquires(&ps2dev->serio->lock)
+static int ps2_do_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
 {
-	int attempt = 0;
 	int error;
 
-	lockdep_assert_held(&ps2dev->serio->lock);
-
-	do {
-		ps2dev->nak = 1;
-		ps2dev->flags |= PS2_FLAG_ACK;
-
-		serio_continue_rx(ps2dev->serio);
-
-		error = serio_write(ps2dev->serio, byte);
-		if (error)
-			dev_dbg(&ps2dev->serio->dev,
-				"failed to write %#02x: %d\n", byte, error);
-		else
-			wait_event_timeout(ps2dev->wait,
-					   !(ps2dev->flags & PS2_FLAG_ACK),
-					   msecs_to_jiffies(timeout));
+	serio_pause_rx(ps2dev->serio);
+	ps2dev->nak = 1;
+	ps2dev->flags |= PS2_FLAG_ACK;
+	serio_continue_rx(ps2dev->serio);
 
-		serio_pause_rx(ps2dev->serio);
-	} while (ps2dev->nak == PS2_RET_NAK && ++attempt < max_attempts);
+	error = serio_write(ps2dev->serio, byte);
+	if (error)
+		dev_dbg(&ps2dev->serio->dev,
+			"failed to write %#02x: %d\n", byte, error);
+	else
+		wait_event_timeout(ps2dev->wait,
+				   !(ps2dev->flags & PS2_FLAG_ACK),
+				   msecs_to_jiffies(timeout));
 
+	serio_pause_rx(ps2dev->serio);
 	ps2dev->flags &= ~PS2_FLAG_ACK;
+	serio_continue_rx(ps2dev->serio);
 
-	if (!error) {
-		switch (ps2dev->nak) {
-		case 0:
-			break;
-		case PS2_RET_NAK:
-			error = -EAGAIN;
-			break;
-		case PS2_RET_ERR:
-			error = -EPROTO;
-			break;
-		default:
-			error = -EIO;
-			break;
-		}
-	}
-
-	if (error || attempt > 1)
-		dev_dbg(&ps2dev->serio->dev,
-			"%02x - %d (%x), attempt %d\n",
-			byte, error, ps2dev->nak, attempt);
-
-	return error;
+	return -ps2dev->nak;
 }
 
 /*
  * ps2_sendbyte() sends a byte to the device and waits for acknowledge.
- * It doesn't handle retransmission, the caller is expected to handle
- * it when needed.
+ * It doesn't handle retransmission, though it could - because if there
+ * is a need for retransmissions device has to be replaced anyway.
  *
  * ps2_sendbyte() can only be called from a process context.
  */
@@ -91,13 +63,9 @@ int ps2_sendbyte(struct ps2dev *ps2dev, u8 byte, unsigned int timeout)
 {
 	int retval;
 
-	serio_pause_rx(ps2dev->serio);
-
-	retval = ps2_do_sendbyte(ps2dev, byte, timeout, 1);
+	retval = ps2_do_sendbyte(ps2dev, byte, timeout);
 	dev_dbg(&ps2dev->serio->dev, "%02x - %x\n", byte, ps2dev->nak);
 
-	serio_continue_rx(ps2dev->serio);
-
 	return retval;
 }
 EXPORT_SYMBOL(ps2_sendbyte);
@@ -232,48 +200,48 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
 	unsigned int timeout;
 	unsigned int send = (command >> 12) & 0xf;
 	unsigned int receive = (command >> 8) & 0xf;
-	int rc;
+	int rc = -1;
 	int i;
 	u8 send_param[16];
 
 	if (receive > sizeof(ps2dev->cmdbuf)) {
 		WARN_ON(1);
-		return -EINVAL;
+		return -1;
 	}
 
 	if (send && !param) {
 		WARN_ON(1);
-		return -EINVAL;
+		return -1;
 	}
 
 	memcpy(send_param, param, send);
 
 	serio_pause_rx(ps2dev->serio);
-
 	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;
 	ps2dev->cmdcnt = receive;
 	if (receive && param)
 		for (i = 0; i < receive; i++)
 			ps2dev->cmdbuf[(receive - 1) - i] = param[i];
+	serio_continue_rx(ps2dev->serio);
 
 	/*
 	 * Some devices (Synaptics) peform the reset before
 	 * ACKing the reset command, and so it can take a long
 	 * time before the ACK arrives.
 	 */
-	rc = ps2_do_sendbyte(ps2dev, command & 0xff,
-			     command == PS2_CMD_RESET_BAT ? 1000 : 200, 2);
-	if (rc)
+	if (ps2_do_sendbyte(ps2dev, command & 0xff,
+			    command == PS2_CMD_RESET_BAT ? 1000 : 200)) {
+		serio_pause_rx(ps2dev->serio);
 		goto out_reset_flags;
+	}
 
 	for (i = 0; i < send; i++) {
-		rc = ps2_do_sendbyte(ps2dev, param[i], 200, 2);
-		if (rc)
+		if (ps2_do_sendbyte(ps2dev, param[i], 200)) {
+			serio_pause_rx(ps2dev->serio);
 			goto out_reset_flags;
+		}
 	}
 
-	serio_continue_rx(ps2dev->serio);
-
 	/*
 	 * The reset command takes a long time to execute.
 	 */
@@ -295,11 +263,8 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
 		for (i = 0; i < receive; i++)
 			param[i] = ps2dev->cmdbuf[(receive - 1) - i];
 
-	if (ps2dev->cmdcnt &&
-	    (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1)) {
-		rc = -EPROTO;
+	if (ps2dev->cmdcnt && (command != PS2_CMD_RESET_BAT || ps2dev->cmdcnt != 1))
 		goto out_reset_flags;
-	}
 
 	rc = 0;
 
@@ -313,11 +278,7 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command)
 		ps2dev->nak, ps2dev->flags,
 		receive, param ?: send_param);
 
-	/*
-	 * ps_command() handles resends itself, so do not leak -EAGAIN
-	 * to the callers.
-	 */
-	return rc != -EAGAIN ? rc : -EPROTO;
+	return rc;
 }
 EXPORT_SYMBOL(__ps2_command);