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Input: cleanup ps2_command() timeout handling in libps2.

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Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
This commit is contained in:
Dmitry Torokhov 2005-06-01 02:39:53 -05:00
parent c611763d04
commit 905ab9d136
1 changed files with 62 additions and 28 deletions
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90
drivers/input/serio/libps2.c
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@ -97,6 +97,66 @@ void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout)
up(&ps2dev->cmd_sem);
}
/*
* ps2_is_keyboard_id() checks received ID byte against the list of
* known keyboard IDs.
*/
static inline int ps2_is_keyboard_id(char id_byte)
{
static char keyboard_ids[] = {
0xab, /* Regular keyboards */
0xac, /* NCD Sun keyboard */
0x2b, /* Trust keyboard, translated */
0x5d, /* Trust keyboard */
0x60, /* NMB SGI keyboard, translated */
0x47, /* NMB SGI keyboard */
};
return memchr(keyboard_ids, id_byte, sizeof(keyboard_ids)) != NULL;
}
/*
* ps2_adjust_timeout() is called after receiving 1st byte of command
* response and tries to reduce remaining timeout to speed up command
* completion.
*/
static int ps2_adjust_timeout(struct ps2dev *ps2dev, int command, int timeout)
{
switch (command) {
case PS2_CMD_RESET_BAT:
/*
* Device has sent the first response byte after
* reset command, reset is thus done, so we can
* shorten the timeout.
* The next byte will come soon (keyboard) or not
* at all (mouse).
*/
if (timeout > msecs_to_jiffies(100))
timeout = msecs_to_jiffies(100);
break;
case PS2_CMD_GETID:
/*
* If device behind the port is not a keyboard there
* won't be 2nd byte of ID response.
*/
if (!ps2_is_keyboard_id(ps2dev->cmdbuf[1])) {
serio_pause_rx(ps2dev->serio);
ps2dev->flags = ps2dev->cmdcnt = 0;
serio_continue_rx(ps2dev->serio);
timeout = 0;
}
break;
default:
break;
}
return timeout;
}
/*
* ps2_command() sends a command and its parameters to the mouse,
* then waits for the response and puts it in the param array.
@ -150,33 +210,7 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
if (ps2dev->cmdcnt && timeout > 0) {
if (command == PS2_CMD_RESET_BAT && timeout > msecs_to_jiffies(100)) {
/*
* Device has sent the first response byte
* after a reset command, reset is thus done,
* shorten the timeout. The next byte will come
* soon (keyboard) or not at all (mouse).
*/
timeout = msecs_to_jiffies(100);
}
if (command == PS2_CMD_GETID &&
ps2dev->cmdbuf[receive - 1] != 0xab && /* Regular keyboards */
ps2dev->cmdbuf[receive - 1] != 0xac && /* NCD Sun keyboard */
ps2dev->cmdbuf[receive - 1] != 0x2b && /* Trust keyboard, translated */
ps2dev->cmdbuf[receive - 1] != 0x5d && /* Trust keyboard */
ps2dev->cmdbuf[receive - 1] != 0x60 && /* NMB SGI keyboard, translated */
ps2dev->cmdbuf[receive - 1] != 0x47) { /* NMB SGI keyboard */
/*
* Device behind the port is not a keyboard
* so we don't need to wait for the 2nd byte
* of ID response.
*/
serio_pause_rx(ps2dev->serio);
ps2dev->flags = ps2dev->cmdcnt = 0;
serio_continue_rx(ps2dev->serio);
}
timeout = ps2_adjust_timeout(ps2dev, command, timeout);
wait_event_timeout(ps2dev->wait,
!(ps2dev->flags & PS2_FLAG_CMD), timeout);
}
@ -190,7 +224,7 @@ int ps2_command(struct ps2dev *ps2dev, unsigned char *param, int command)
rc = 0;
out:
out:
serio_pause_rx(ps2dev->serio);
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);