b43: Fix ofdmtab write regression

commit f04b3787bbce4567e28069a9ec97dcd804626ac7 introduced
a regression for the ofdmtable writing.

It incorrectly removed the writing of the high 16bits for
a 32bit table write and initialized the direction identifier
too late.

This patch does also some cleanups to make the code much more
readable and adds a few comments, so non rocket scientists are
also able to understand what this address caching is all about.

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/b43/tables.c b/drivers/net/wireless/b43/tables.c
index be9c7eb..fd5595b 100644
--- a/drivers/net/wireless/b43/tables.c
+++ b/drivers/net/wireless/b43/tables.c
@@ -381,13 +381,17 @@
 	u16 addr;
 
 	addr = table + offset;
-	if (addr - 1 != phy->ofdm_addr || phy->ofdm_valid != 1) {
+	if ((phy->ofdmtab_addr_direction != B43_OFDMTAB_DIRECTION_READ) ||
+	    (addr - 1 != phy->ofdmtab_addr)) {
+		/* The hardware has a different address in memory. Update it. */
 		b43_phy_write(dev, B43_PHY_OTABLECTL, addr);
-		phy->ofdm_valid = 1;
+		phy->ofdmtab_addr_direction = B43_OFDMTAB_DIRECTION_READ;
 	}
-	phy->ofdm_addr = addr;
+	phy->ofdmtab_addr = addr;
 
 	return b43_phy_read(dev, B43_PHY_OTABLEI);
+
+	/* Some compiletime assertions... */
 	assert_sizes();
 }
 
@@ -398,11 +402,13 @@
 	u16 addr;
 
 	addr = table + offset;
-	if (addr - 1 != phy->ofdm_addr || phy->ofdm_valid != 2) {
+	if ((phy->ofdmtab_addr_direction != B43_OFDMTAB_DIRECTION_WRITE) ||
+	    (addr -1 != phy->ofdmtab_addr)) {
+		/* The hardware has a different address in memory. Update it. */
 		b43_phy_write(dev, B43_PHY_OTABLECTL, addr);
-		phy->ofdm_valid = 2;
+		phy->ofdmtab_addr_direction = B43_OFDMTAB_DIRECTION_WRITE;
 	}
-	phy->ofdm_addr = addr;
+	phy->ofdmtab_addr = addr;
 	b43_phy_write(dev, B43_PHY_OTABLEI, value);
 }
 
@@ -413,11 +419,13 @@
 	u16 addr;
 
 	addr = table + offset;
-	if (addr - 1 != phy->ofdm_addr || phy->ofdm_valid != 1) {
+	if ((phy->ofdmtab_addr_direction != B43_OFDMTAB_DIRECTION_READ) ||
+	    (addr - 1 != phy->ofdmtab_addr)) {
+		/* The hardware has a different address in memory. Update it. */
 		b43_phy_write(dev, B43_PHY_OTABLECTL, addr);
-		phy->ofdm_valid = 1;
+		phy->ofdmtab_addr_direction = B43_OFDMTAB_DIRECTION_READ;
 	}
-	phy->ofdm_addr = addr;
+	phy->ofdmtab_addr = addr;
 	ret = b43_phy_read(dev, B43_PHY_OTABLEQ);
 	ret <<= 16;
 	ret |= b43_phy_read(dev, B43_PHY_OTABLEI);
@@ -432,13 +440,16 @@
 	u16 addr;
 
 	addr = table + offset;
-	if (addr - 1 != phy->ofdm_addr || phy->ofdm_valid != 2) {
+	if ((phy->ofdmtab_addr_direction != B43_OFDMTAB_DIRECTION_WRITE) ||
+	    (addr - 1 != phy->ofdmtab_addr)) {
+		/* The hardware has a different address in memory. Update it. */
 		b43_phy_write(dev, B43_PHY_OTABLECTL, addr);
-		phy->ofdm_valid = 2;
+		phy->ofdmtab_addr_direction = B43_OFDMTAB_DIRECTION_WRITE;
 	}
-	phy->ofdm_addr = addr;
+	phy->ofdmtab_addr = addr;
 
 	b43_phy_write(dev, B43_PHY_OTABLEI, value);
+	b43_phy_write(dev, B43_PHY_OTABLEQ, (value >> 16));
 }
 
 u16 b43_gtab_read(struct b43_wldev *dev, u16 table, u16 offset)