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

From: Raul E Rangel
Date: Thu May 18 2023 - 13:21:28 EST


On Thu, May 11, 2023 at 11:52:42AM -0700, Dmitry Torokhov wrote:
> 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;
Reviewed-by: Raul E Rangel <rrangel@xxxxxxxxxxxx>