Commit df9fe0e6 authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: libps2 - rework handling of command response 



It is not entirely correct that libps2 sets PS2_FLAG_CMD1 after
the device acknowledges each byte sent to the device by the host.
Rework the code so that PS2_FLAG_CMD1 and PS2_FLAG_CMD are set only once,
at the beginning of PS/2 command execution.

Reviewed-by: default avatarRaul E Rangel <rrangel@chromium.org>
Link: https://lore.kernel.org/r/20230511185252.386941-4-dmitry.torokhov@gmail.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent fc522f3b

drivers/input/serio/libps2.c

+10 −8
Original line number Diff line number Diff line
@@ -247,14 +247,19 @@ int __ps2_command(struct ps2dev *ps2dev, u8 *param, unsigned int command) 


	serio_pause_rx(ps2dev->serio);



	/* Some mice do not ACK the "get ID" command, prepare to handle this. */

	ps2dev->flags = command == PS2_CMD_GETID ? PS2_FLAG_WAITID : 0;

	ps2dev->cmdcnt = receive;

	if (receive && param)

	if (receive) {

		/* Indicate that we expect response to the command. */

		ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;

		if (param)

			for (i = 0; i < receive; i++)

				ps2dev->cmdbuf[(receive - 1) - i] = param[i];

	}



	/*

	 * Some devices (Synaptics) peform the reset before

	 * Some devices (Synaptics) perform the reset before

	 * ACKing the reset command, and so it can take a long

	 * time before the ACK arrives.

	 */
@@ -434,11 +439,8 @@ bool ps2_handle_ack(struct ps2dev *ps2dev, u8 data) 
		return true;

	}



	if (!ps2dev->nak) {

	if (!ps2dev->nak)

		ps2dev->flags &= ~PS2_FLAG_NAK;

		if (ps2dev->cmdcnt)

			ps2dev->flags |= PS2_FLAG_CMD | PS2_FLAG_CMD1;

	}



	ps2dev->flags &= ~PS2_FLAG_ACK;

	wake_up(&ps2dev->wait);