i7300_idle: Cleanup based review comments

Cleanup of i7300 idle driver based on review comments from Randy Dunlap,
Andi Kleen and Len Brown.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

2 files changed, 24 insertions, 20 deletions

diff --git a/drivers/idle/Kconfig b/drivers/idle/Kconfig
index f5b26dd579e4..108264de0ac9 100644
--- a/drivers/idle/Kconfig
+++ b/drivers/idle/Kconfig
@@ -5,12 +5,13 @@ config I7300_IDLE_IOAT_CHANNEL
         bool
 
 config I7300_IDLE
-        tristate "Intel chipset idle power saving driver"
+        tristate "Intel chipset idle memory power saving driver"
         select I7300_IDLE_IOAT_CHANNEL
-        depends on X86_64
+        depends on X86_64 && EXPERIMENTAL
         help
-          Enable idle power savings with certain Intel server chipsets.
-          The chipset must have I/O AT support, such as the Intel 7300.
-          The power savings depends on the type and quantity of DRAM devices.
+          Enable memory power savings when idle with certain Intel server
+          chipsets. The chipset must have I/O AT support, such as the
+          Intel 7300. The power savings depends on the type and quantity of
+          DRAM devices.
 
 endmenu
diff --git a/drivers/idle/i7300_idle.c b/drivers/idle/i7300_idle.c
index 79d47f284cd6..fb176f6ef9f8 100644
--- a/drivers/idle/i7300_idle.c
+++ b/drivers/idle/i7300_idle.c
@@ -35,6 +35,8 @@
 #define I7300_IDLE_DRIVER_VERSION       "1.55"
 #define I7300_PRINT                     "i7300_idle:"
 
+#define MAX_STOP_RETRIES        10
+
 static int debug;
 module_param_named(debug, debug, uint, 0644);
 MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
@@ -47,12 +49,12 @@ MODULE_PARM_DESC(debug, "Enable debug printks in this driver");
  *  0 = No throttling
  *  1 = Throttle when > 4 activations per eval window (Maximum throttling)
  *  2 = Throttle when > 8 activations
- *  168 = Throttle when > 168 activations (Minimum throttling)
+ *  168 = Throttle when > 672 activations (Minimum throttling)
  */
-#define MAX_THRTLWLIMIT         168
-static uint i7300_idle_thrtlowlm = 1;
-module_param_named(thrtlwlimit, i7300_idle_thrtlowlm, uint, 0644);
-MODULE_PARM_DESC(thrtlwlimit,
+#define MAX_THROTTLE_LOW_LIMIT          168
+static uint throttle_low_limit = 1;
+module_param_named(throttle_low_limit, throttle_low_limit, uint, 0644);
+MODULE_PARM_DESC(throttle_low_limit,
                 "Value for THRTLOWLM activation field "
                 "(0 = disable throttle, 1 = Max throttle, 168 = Min throttle)");
 
@@ -111,9 +113,9 @@ static int i7300_idle_ioat_start(void)
 static void i7300_idle_ioat_stop(void)
 {
         int i;
-        u8 sts;
+        u64 sts;
 
-        for (i = 0; i < 5; i++) {
+        for (i = 0; i < MAX_STOP_RETRIES; i++) {
                 writeb(IOAT_CHANCMD_RESET,
                         ioat_chanbase + IOAT1_CHANCMD_OFFSET);
 
@@ -127,9 +129,10 @@ static void i7300_idle_ioat_stop(void)
 
         }
 
-        if (i == 5)
-                dprintk("failed to suspend+reset I/O AT after 5 retries\n");
-
+        if (i == MAX_STOP_RETRIES) {
+                dprintk("failed to stop I/O AT after %d retries\n",
+                        MAX_STOP_RETRIES);
+        }
 }
 
 /* Test I/O AT by copying 1024 byte from 2k to 1k */
@@ -276,7 +279,7 @@ static void __exit i7300_idle_ioat_exit(void)
         i7300_idle_ioat_stop();
 
         /* Wait for a while for the channel to halt before releasing */
-        for (i = 0; i < 10; i++) {
+        for (i = 0; i < MAX_STOP_RETRIES; i++) {
                 writeb(IOAT_CHANCMD_RESET,
                        ioat_chanbase + IOAT1_CHANCMD_OFFSET);
 
@@ -390,9 +393,9 @@ static void i7300_idle_start(void)
         new_ctl = i7300_idle_thrtctl_saved & ~DIMM_THRTCTL_THRMHUNT;
         pci_write_config_byte(fbd_dev, DIMM_THRTCTL, new_ctl);
 
-        limit = i7300_idle_thrtlowlm;
-        if (unlikely(limit > MAX_THRTLWLIMIT))
-                limit = MAX_THRTLWLIMIT;
+        limit = throttle_low_limit;
+        if (unlikely(limit > MAX_THROTTLE_LOW_LIMIT))
+                limit = MAX_THROTTLE_LOW_LIMIT;
 
         pci_write_config_byte(fbd_dev, DIMM_THRTLOW, limit);
 
@@ -441,7 +444,7 @@ static int i7300_idle_notifier(struct notifier_block *nb, unsigned long val,
         static ktime_t idle_begin_time;
         static int time_init = 1;
 
-        if (!i7300_idle_thrtlowlm)
+        if (!throttle_low_limit)
                 return 0;
 
         if (unlikely(time_init)) {