watchdog: sch56xx: Remove unnecessary checks for register changes

Since the watchdog core keeps track of the watchdog's active state, start/stop
will never get called when no changes are necessary. So we can remove the
check for the output_enable register changing before writing it (which is
an expensive operation).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>

1 files changed, 16 insertions, 25 deletions

diff --git a/drivers/hwmon/sch56xx-common.c b/drivers/hwmon/sch56xx-common.c
index 419a8e8f5191..35846cbf1c9c 100644
--- a/drivers/hwmon/sch56xx-common.c
+++ b/drivers/hwmon/sch56xx-common.c
@@ -334,18 +334,14 @@ static int watchdog_start(struct watchdog_device *wddev)
         if (ret)
                 goto leave;
 
-        /* 2. Enable output (if not already enabled) */
-        if (!(data->watchdog_output_enable & SCH56XX_WDOG_OUTPUT_ENABLE)) {
-                val = data->watchdog_output_enable |
-                      SCH56XX_WDOG_OUTPUT_ENABLE;
-                ret = sch56xx_write_virtual_reg(data->addr,
-                                                SCH56XX_REG_WDOG_OUTPUT_ENABLE,
-                                                val);
-                if (ret)
-                        goto leave;
+        /* 2. Enable output */
+        val = data->watchdog_output_enable | SCH56XX_WDOG_OUTPUT_ENABLE;
+        ret = sch56xx_write_virtual_reg(data->addr,
+                                        SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
+        if (ret)
+                goto leave;
 
-                data->watchdog_output_enable = val;
-        }
+        data->watchdog_output_enable = val;
 
         /* 3. Clear the watchdog event bit if set */
         val = inb(data->addr + 9);
@@ -377,21 +373,16 @@ static int watchdog_stop(struct watchdog_device *wddev)
         int ret = 0;
         u8 val;
 
-        if (data->watchdog_output_enable & SCH56XX_WDOG_OUTPUT_ENABLE) {
-                val = data->watchdog_output_enable &
-                      ~SCH56XX_WDOG_OUTPUT_ENABLE;
-                mutex_lock(data->io_lock);
-                ret = sch56xx_write_virtual_reg(data->addr,
-                                                SCH56XX_REG_WDOG_OUTPUT_ENABLE,
-                                                val);
-                mutex_unlock(data->io_lock);
-                if (ret)
-                        return ret;
-
-                data->watchdog_output_enable = val;
-        }
+        val = data->watchdog_output_enable & ~SCH56XX_WDOG_OUTPUT_ENABLE;
+        mutex_lock(data->io_lock);
+        ret = sch56xx_write_virtual_reg(data->addr,
+                                        SCH56XX_REG_WDOG_OUTPUT_ENABLE, val);
+        mutex_unlock(data->io_lock);
+        if (ret)
+                return ret;
 
-        return ret;
+        data->watchdog_output_enable = val;
+        return 0;
 }
 
 static const struct watchdog_ops watchdog_ops = {