diff options
| -rw-r--r-- | drivers/input/serio/libps2.c | 90 |
1 files changed, 62 insertions, 28 deletions
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c index 92b92ee0379..d4c990f7c85 100644 --- a/drivers/input/serio/libps2.c +++ b/drivers/input/serio/libps2.c @@ -98,6 +98,66 @@ void ps2_drain(struct ps2dev *ps2dev, int maxbytes, int timeout) } /* + * 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); |