From 4a6bf80baf1e0f06fce64557f32c57035f07bc53 Mon Sep 17 00:00:00 2001
From: Henrik Rydberg <rydberg@euromail.se>
Date: Sat, 18 Oct 2008 20:27:38 -0700
Subject: [PATCH] --- yaml --- r: 115900 b: refs/heads/master c:
 84d2d7f2ee98dc9bd799790c89b5eb8280af2d37 h: refs/heads/master v: v3

---
 [refs]                         |  2 +-
 trunk/drivers/hwmon/applesmc.c | 32 ++++++++++++++++++++++++--------
 2 files changed, 25 insertions(+), 9 deletions(-)

diff --git a/[refs] b/[refs]
index 99aeb66cee8d..41263f7b26d8 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 05224091af06177c0ce7c1fae1f498455b47a6be
+refs/heads/master: 84d2d7f2ee98dc9bd799790c89b5eb8280af2d37
diff --git a/trunk/drivers/hwmon/applesmc.c b/trunk/drivers/hwmon/applesmc.c
index b401975bc0da..d5bd0cadbf31 100644
--- a/trunk/drivers/hwmon/applesmc.c
+++ b/trunk/drivers/hwmon/applesmc.c
@@ -190,6 +190,26 @@ static int __wait_status(u8 val)
 	return -EIO;
 }
 
+/*
+ * special treatment of command port - on newer macbooks, it seems necessary
+ * to resend the command byte before polling the status again. Callers must
+ * hold applesmc_lock.
+ */
+static int send_command(u8 cmd)
+{
+	int i;
+	for (i = 0; i < 1000; i++) {
+		outb(cmd, APPLESMC_CMD_PORT);
+		udelay(5);
+		if ((inb(APPLESMC_CMD_PORT) & APPLESMC_STATUS_MASK) == 0x0c)
+			return 0;
+		udelay(5);
+	}
+	printk(KERN_WARNING "applesmc: command failed: %x -> %x\n",
+		cmd, inb(APPLESMC_CMD_PORT));
+	return -EIO;
+}
+
 /*
  * applesmc_read_key - reads len bytes from a given key, and put them in buffer.
  * Returns zero on success or a negative error on failure. Callers must
@@ -205,8 +225,7 @@ static int applesmc_read_key(const char* key, u8* buffer, u8 len)
 		return -EINVAL;
 	}
 
-	outb(APPLESMC_READ_CMD, APPLESMC_CMD_PORT);
-	if (__wait_status(0x0c))
+	if (send_command(APPLESMC_READ_CMD))
 		return -EIO;
 
 	for (i = 0; i < 4; i++) {
@@ -249,8 +268,7 @@ static int applesmc_write_key(const char* key, u8* buffer, u8 len)
 		return -EINVAL;
 	}
 
-	outb(APPLESMC_WRITE_CMD, APPLESMC_CMD_PORT);
-	if (__wait_status(0x0c))
+	if (send_command(APPLESMC_WRITE_CMD))
 		return -EIO;
 
 	for (i = 0; i < 4; i++) {
@@ -284,8 +302,7 @@ static int applesmc_get_key_at_index(int index, char* key)
 	readkey[2] = index >> 8;
 	readkey[3] = index;
 
-	outb(APPLESMC_GET_KEY_BY_INDEX_CMD, APPLESMC_CMD_PORT);
-	if (__wait_status(0x0c))
+	if (send_command(APPLESMC_GET_KEY_BY_INDEX_CMD))
 		return -EIO;
 
 	for (i = 0; i < 4; i++) {
@@ -315,8 +332,7 @@ static int applesmc_get_key_type(char* key, char* type)
 {
 	int i;
 
-	outb(APPLESMC_GET_KEY_TYPE_CMD, APPLESMC_CMD_PORT);
-	if (__wait_status(0x0c))
+	if (send_command(APPLESMC_GET_KEY_TYPE_CMD))
 		return -EIO;
 
 	for (i = 0; i < 4; i++) {