Commit c472d33b authored by Dmitry Torokhov's avatar Dmitry Torokhov
Browse files

Input: cypress_ps2 - fix waiting for command response 



Commit 8bccf667 ("Input: cypress_ps2 - report timeouts when reading
command status") uncovered an existing problem with cypress_ps2 driver:
it tries waiting on a PS/2 device waitqueue without using the rest of
libps2. Unfortunately without it nobody signals wakeup for the
waiting process, and each "extended" command was timing out. But the
rest of the code simply did not notice it.

Fix this by switching from homegrown way of sending request to get
command response and reading it to standard ps2_command() which does
the right thing.

Reported-by: default avatarWoody Suwalski <terraluna977@gmail.com>
Tested-by: default avatarWoody Suwalski <terraluna977@gmail.com>
Fixes: 8bccf667 ("Input: cypress_ps2 - report timeouts when reading command status")
Link: https://lore.kernel.org/r/a8252e0f-dab4-ef5e-2aa1-407a6f4c7204@gmail.com


Signed-off-by: default avatarDmitry Torokhov <dmitry.torokhov@gmail.com>
parent 4e870e6b

drivers/input/mouse/cypress_ps2.c

+13 −45
Original line number Diff line number Diff line
@@ -91,48 +91,6 @@ static int cypress_ps2_ext_cmd(struct psmouse *psmouse, u8 prefix, u8 nibble) 
	return rc;

}



static int cypress_ps2_read_cmd_status(struct psmouse *psmouse,

				       u8 cmd, u8 *param)

{

	struct ps2dev *ps2dev = &psmouse->ps2dev;

	enum psmouse_state old_state;

	int pktsize;

	int rc;



	ps2_begin_command(ps2dev);



	old_state = psmouse->state;

	psmouse->state = PSMOUSE_CMD_MODE;

	psmouse->pktcnt = 0;



	pktsize = (cmd == CYTP_CMD_READ_TP_METRICS) ? 8 : 3;

	memset(param, 0, pktsize);



	rc = cypress_ps2_sendbyte(psmouse, PSMOUSE_CMD_GETINFO & 0xff);

	if (rc)

		goto out;



	if (!wait_event_timeout(ps2dev->wait,

				psmouse->pktcnt >= pktsize,

				msecs_to_jiffies(CYTP_CMD_TIMEOUT))) {

		rc = -ETIMEDOUT;

		goto out;

	}



	memcpy(param, psmouse->packet, pktsize);



	psmouse_dbg(psmouse, "Command 0x%02x response data (0x): %*ph\n",

			cmd, pktsize, param);



out:

	psmouse->state = old_state;

	psmouse->pktcnt = 0;



	ps2_end_command(ps2dev);



	return rc;

}



static bool cypress_verify_cmd_state(struct psmouse *psmouse, u8 cmd, u8* param)

{

	bool rate_match = false;
@@ -166,6 +124,8 @@ static bool cypress_verify_cmd_state(struct psmouse *psmouse, u8 cmd, u8* param) 
static int cypress_send_ext_cmd(struct psmouse *psmouse, u8 cmd, u8 *param)

{

	u8 cmd_prefix = PSMOUSE_CMD_SETRES & 0xff;

	unsigned int resp_size = cmd == CYTP_CMD_READ_TP_METRICS ? 8 : 3;

	unsigned int ps2_cmd = (PSMOUSE_CMD_GETINFO & 0xff) | (resp_size << 8);

	int tries = CYTP_PS2_CMD_TRIES;

	int error;
@@ -179,10 +139,18 @@ static int cypress_send_ext_cmd(struct psmouse *psmouse, u8 cmd, u8 *param) 
		cypress_ps2_ext_cmd(psmouse, cmd_prefix, DECODE_CMD_BB(cmd));

		cypress_ps2_ext_cmd(psmouse, cmd_prefix, DECODE_CMD_AA(cmd));



		error = cypress_ps2_read_cmd_status(psmouse, cmd, param);

		if (!error && cypress_verify_cmd_state(psmouse, cmd, param))

			return 0;

		error = ps2_command(&psmouse->ps2dev, param, ps2_cmd);

		if (error) {

			psmouse_dbg(psmouse, "Command 0x%02x failed: %d\n",

				    cmd, error);

		} else {

			psmouse_dbg(psmouse,

				    "Command 0x%02x response data (0x): %*ph\n",

				    cmd, resp_size, param);



			if (cypress_verify_cmd_state(psmouse, cmd, param))

				return 0;

		}

	} while (--tries > 0);



	return -EIO;