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Input: cypress_ps2 - fix waiting for command response

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Commit 8bccf667f6 ("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: Woody Suwalski <terraluna977@gmail.com>
Tested-by: Woody Suwalski <terraluna977@gmail.com>
Fixes: 8bccf667f6 ("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: Dmitry Torokhov <dmitry.torokhov@gmail.com>
This commit is contained in:
Dmitry Torokhov 2024-08-29 08:38:54 -07:00
parent 4e870e6bbe
commit c472d33bcb
1 changed files with 13 additions and 45 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

58
drivers/input/mouse/cypress_ps2.c
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@ -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;