Input: cleanup ps2_command() timeout handling in libps2.
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
diff --git a/drivers/input/serio/libps2.c b/drivers/input/serio/libps2.c
index 92b92ee..d4c990f 100644
--- a/drivers/input/serio/libps2.c
+++ b/drivers/input/serio/libps2.c
@@ -98,6 +98,66 @@
}
/*
+ * 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 @@
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 @@
rc = 0;
-out:
+ out:
serio_pause_rx(ps2dev->serio);
ps2dev->flags = 0;
serio_continue_rx(ps2dev->serio);