Input: cyapa - use time based retry loop

Using counter based retry loops for peripherals results in the delay
being significantly overrun during high-load situations where delay
functions tend to be vary imprecise and overrun there timeouts. So
condition the termination on the actual condition of 2s for the
re-calibration to have been successful.

As this is a very long delay there is no advantage in using
high-resolution timers thus switching this to msleep().

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/mouse/cyapa_gen3.c b/drivers/input/mouse/cyapa_gen3.c
index f9600753eca54937648b95a4632932312d7e50c4..a47b06f4ed519f2a8247e66b28be277f7d6fbda7 100644 (file)
--- a/drivers/input/mouse/cyapa_gen3.c
+++ b/drivers/input/mouse/cyapa_gen3.c
@@ -789,7 +789,7 @@ static ssize_t cyapa_gen3_do_calibrate(struct device *dev,
                                     const char *buf, size_t count)
 {
        struct cyapa *cyapa = dev_get_drvdata(dev);
-       int tries;
+       unsigned long timeout;
        int ret;
 
        ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
@@ -812,31 +812,28 @@ static ssize_t cyapa_gen3_do_calibrate(struct device *dev,
                goto out;
        }
 
-       tries = 20;  /* max recalibration timeout 2s. */
+       /* max recalibration timeout 2s. */
+       timeout = jiffies + 2 * HZ;
        do {
                /*
                 * For this recalibration, the max time will not exceed 2s.
                 * The average time is approximately 500 - 700 ms, and we
                 * will check the status every 100 - 200ms.
                 */
-               usleep_range(100000, 200000);
-
+               msleep(100);
                ret = cyapa_read_byte(cyapa, CYAPA_CMD_DEV_STATUS);
                if (ret < 0) {
-                       dev_err(dev, "Error reading dev status: %d\n",
-                               ret);
+                       dev_err(dev, "Error reading dev status: %d\n", ret);
                        goto out;
                }
-               if ((ret & CYAPA_DEV_NORMAL) == CYAPA_DEV_NORMAL)
-                       break;
-       } while (--tries);
+               if ((ret & CYAPA_DEV_NORMAL) == CYAPA_DEV_NORMAL) {
+                       dev_dbg(dev, "Calibration successful.\n");
+                       goto out;
+               }
+       } while (time_is_after_jiffies(timeout));
 
-       if (tries == 0) {
-               dev_err(dev, "Failed to calibrate. Timeout.\n");
-               ret = -ETIMEDOUT;
-               goto out;
-       }
-       dev_dbg(dev, "Calibration successful.\n");
+       dev_err(dev, "Failed to calibrate. Timeout.\n");
+       ret = -ETIMEDOUT;
 
 out:
        return ret < 0 ? ret : count;