Input: i8042 - don't use negation to mark AUX data

Currently i8042_command() negates data coming from the AUX port
of keyboard controller; this is not a very reliable indicator.
Change i8042_command() to fail if response to I8042_CMD_AUX_LOOP
is not coming from AUX channel and get rid of negation.

Based on patch by Vojtech Pavlik.

Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index a9bf549..708a1d3 100644 (file)
--- a/drivers/input/serio/i8042.c
+++ b/drivers/input/serio/i8042.c
@@ -100,7 +100,7 @@ struct i8042_port {
 static struct i8042_port i8042_ports[I8042_NUM_PORTS] = {
        {
                .disable        = I8042_CTR_KBDDIS,
-               .irqen          = I8042_CTR_KBDINT,
+               .irqen          = I8042_CTR_KBDINT,
                .mux            = -1,
                .name           = "KBD",
        },
@@ -191,41 +191,45 @@ static int i8042_flush(void)
 static int i8042_command(unsigned char *param, int command)
 {
        unsigned long flags;
-       int retval = 0, i = 0;
+       int i, retval, auxerr = 0;
 
        if (i8042_noloop && command == I8042_CMD_AUX_LOOP)
                return -1;
 
        spin_lock_irqsave(&i8042_lock, flags);
 
-       retval = i8042_wait_write();
-       if (!retval) {
-               dbg("%02x -> i8042 (command)", command & 0xff);
-               i8042_write_command(command & 0xff);
+       if ((retval = i8042_wait_write()))
+               goto out;
+
+       dbg("%02x -> i8042 (command)", command & 0xff);
+       i8042_write_command(command & 0xff);
+
+       for (i = 0; i < ((command >> 12) & 0xf); i++) {
+               if ((retval = i8042_wait_write()))
+                       goto out;
+               dbg("%02x -> i8042 (parameter)", param[i]);
+               i8042_write_data(param[i]);
        }
 
-       if (!retval)
-               for (i = 0; i < ((command >> 12) & 0xf); i++) {
-                       if ((retval = i8042_wait_write())) break;
-                       dbg("%02x -> i8042 (parameter)", param[i]);
-                       i8042_write_data(param[i]);
-               }
+       for (i = 0; i < ((command >> 8) & 0xf); i++) {
+               if ((retval = i8042_wait_read()))
+                       goto out;
 
-       if (!retval)
-               for (i = 0; i < ((command >> 8) & 0xf); i++) {
-                       if ((retval = i8042_wait_read())) break;
-                       if (i8042_read_status() & I8042_STR_AUXDATA)
-                               param[i] = ~i8042_read_data();
-                       else
-                               param[i] = i8042_read_data();
-                       dbg("%02x <- i8042 (return)", param[i]);
+               if (command == I8042_CMD_AUX_LOOP &&
+                   !(i8042_read_status() & I8042_STR_AUXDATA)) {
+                       retval = auxerr = -1;
+                       goto out;
                }
 
-       spin_unlock_irqrestore(&i8042_lock, flags);
+               param[i] = i8042_read_data();
+               dbg("%02x <- i8042 (return)", param[i]);
+       }
 
        if (retval)
-               dbg("     -- i8042 (timeout)");
+               dbg("     -- i8042 (%s)", auxerr ? "auxerr" : "timeout");
 
+ out:
+       spin_unlock_irqrestore(&i8042_lock, flags);
        return retval;
 }
 
@@ -507,17 +511,17 @@ static int i8042_set_mux_mode(unsigned int mode, unsigned char *mux_version)
  */
 
        param = 0xf0;
-       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != 0x0f)
+       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != 0xf0)
                return -1;
        param = mode ? 0x56 : 0xf6;
-       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != (mode ? 0xa9 : 0x09))
+       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != (mode ? 0x56 : 0xf6))
                return -1;
        param = mode ? 0xa4 : 0xa5;
-       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param == (mode ? 0x5b : 0x5a))
+       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param == (mode ? 0xa4 : 0xa5))
                return -1;
 
        if (mux_version)
-               *mux_version = ~param;
+               *mux_version = param;
 
        return 0;
 }
@@ -619,7 +623,7 @@ static int __init i8042_check_aux(void)
  */
 
        param = 0x5a;
-       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != 0xa5) {
+       if (i8042_command(&param, I8042_CMD_AUX_LOOP) || param != 0x5a) {
 
 /*
  * External connection test - filters out AT-soldered PS/2 i8042's
@@ -630,7 +634,7 @@ static int __init i8042_check_aux(void)
  */
 
                if (i8042_command(&param, I8042_CMD_AUX_TEST)
-                       || (param && param != 0xfa && param != 0xff))
+                       || (param && param != 0xfa && param != 0xff))
                                return -1;
        }