1 files changed, 11 insertions, 15 deletions

diff --git a/drivers/hwmon/w83627ehf.c b/drivers/hwmon/w83627ehf.c
index 1128eac7023b..5a627b9db3e8 100644
--- a/drivers/hwmon/w83627ehf.c
+++ b/drivers/hwmon/w83627ehf.c
@@ -304,6 +304,7 @@ struct w83627ehf_data {
         unsigned long last_updated;     /* In jiffies */
 
         /* Register values */
+        u8 bank;                /* current register bank */
         u8 in_num;              /* number of in inputs we have */
         u8 in[10];              /* Register value */
         u8 in_max[10];          /* Register value */
@@ -347,21 +348,19 @@ struct w83627ehf_sio_data {
         enum kinds kind;
 };
 
-/* Registers 0x50-0x5f are banked */
+/*
+ * On older chips, only registers 0x50-0x5f are banked.
+ * On more recent chips, all registers are banked.
+ * Assume that is the case and set the bank number for each access.
+ * Cache the bank number so it only needs to be set if it changes.
+ */
 static inline void w83627ehf_set_bank(struct w83627ehf_data *data, u16 reg)
 {
-        if ((reg & 0x00f0) == 0x50) {
-                outb_p(W83627EHF_REG_BANK, data->addr + ADDR_REG_OFFSET);
-                outb_p(reg >> 8, data->addr + DATA_REG_OFFSET);
-        }
-}
-
-/* Not strictly necessary, but play it safe for now */
-static inline void w83627ehf_reset_bank(struct w83627ehf_data *data, u16 reg)
-{
-        if (reg & 0xff00) {
+        u8 bank = reg >> 8;
+        if (data->bank != bank) {
                 outb_p(W83627EHF_REG_BANK, data->addr + ADDR_REG_OFFSET);
-                outb_p(0, data->addr + DATA_REG_OFFSET);
+                outb_p(bank, data->addr + DATA_REG_OFFSET);
+                data->bank = bank;
         }
 }
 
@@ -379,10 +378,8 @@ static u16 w83627ehf_read_value(struct w83627ehf_data *data, u16 reg)
                        data->addr + ADDR_REG_OFFSET);
                 res = (res << 8) + inb_p(data->addr + DATA_REG_OFFSET);
         }
-        w83627ehf_reset_bank(data, reg);
 
         mutex_unlock(&data->lock);
-
         return res;
 }
 
@@ -401,7 +398,6 @@ static int w83627ehf_write_value(struct w83627ehf_data *data, u16 reg,
                        data->addr + ADDR_REG_OFFSET);
         }
         outb_p(value & 0xff, data->addr + DATA_REG_OFFSET);
-        w83627ehf_reset_bank(data, reg);
 
         mutex_unlock(&data->lock);
         return 0;