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>

1 files changed, 32 insertions, 28 deletions

diff --git a/drivers/input/serio/i8042.c b/drivers/input/serio/i8042.c
index a9bf549c8d..708a1d3bea 100644
--- 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;
         }