drivers/rtc/rtc-ab8500.c: change msleep() to usleep_range()

The resolution of msleep is related to HZ, so with HZ set to 100 any
msleep of less than 10ms will become ~10ms.  This is not what we want.
Use the hrtimer-based usleep_range() and allow for some slack in the
non-critical path so we have more control of what is happening here.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Cc: Jonas Aaberg <jonas.aberg@stericsson.com>
Cc: Alessandro Zummo <a.zummo@towertech.it>
Cc: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/drivers/rtc/rtc-ab8500.c b/drivers/rtc/rtc-ab8500.c
index 84c7eaea50a52aed310dfb54e7be4826625fce67..6315b9c46aa77c9fb16c5a7d1a12b364cc15aaaa 100644 (file)
--- a/drivers/rtc/rtc-ab8500.c
+++ b/drivers/rtc/rtc-ab8500.c
@@ -90,7 +90,7 @@ static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
 
        /* Early AB8500 chips will not clear the rtc read request bit */
        if (abx500_get_chip_id(dev) == 0) {
-               msleep(1);
+               usleep_range(1000, 1000);
        } else {
                /* Wait for some cycles after enabling the rtc read in ab8500 */
                while (time_before(jiffies, timeout)) {
@@ -102,7 +102,7 @@ static int ab8500_rtc_read_time(struct device *dev, struct rtc_time *tm)
                        if (!(value & RTC_READ_REQUEST))
                                break;
 
-                       msleep(1);
+                       usleep_range(1000, 5000);
                }
        }
 
@@ -295,7 +295,7 @@ static int __devinit ab8500_rtc_probe(struct platform_device *pdev)
                return err;
 
        /* Wait for reset by the PorRtc */
-       msleep(1);
+       usleep_range(1000, 5000);
 
        err = abx500_get_register_interruptible(&pdev->dev, AB8500_RTC,
                AB8500_RTC_STAT_REG, &rtc_ctrl);