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    Subject[PATCH v4 03/10] rtc: max77686: Use usleep_range() instead of msleep()
    Date
    Documentation/timers/timers-howto.txt suggest to use usleep_range()
    instead of msleep() for small msec (1ms - 20ms) since msleep() will
    often sleep for 20ms for any value in that range.

    This is fine in this case since 16ms is the _minimum_ delay required
    by max77686 for an RTC update but by using usleep_range() instead of
    msleep(), the driver can support other RTC IP blocks with a shorter
    minimum delay (i.e: in the range of usecs instead of msecs).

    Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
    Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
    Tested-by: Krzysztof Kozlowski <k.kozlowski@samsung.com>
    Reviewed-by: Andi Shyti <andi.shyti@samsung.com>

    ---

    Changes in v4:
    - Add Andi Shyti's Reviewed-by to patch #3.

    Changes in v3:
    - Add Krzysztof Kozlowski's Tested-by tag to patch #3.
    - Add Laxman Dewangan's Acked-by tag to patch #3.

    Changes in v2:
    - Add Krzysztof Kozlowski's Reviewed-by tag to patch #3.
    - Fix typo error in changelog. Suggested by Krzysztof Kozlowski.

    drivers/rtc/rtc-max77686.c | 5 +++--
    1 file changed, 3 insertions(+), 2 deletions(-)

    diff --git a/drivers/rtc/rtc-max77686.c b/drivers/rtc/rtc-max77686.c
    index d84a50c9f7f7..025a17a95da3 100644
    --- a/drivers/rtc/rtc-max77686.c
    +++ b/drivers/rtc/rtc-max77686.c
    @@ -41,7 +41,7 @@
    #define ALARM_ENABLE_SHIFT 7
    #define ALARM_ENABLE_MASK (1 << ALARM_ENABLE_SHIFT)

    -#define MAX77686_RTC_UPDATE_DELAY 16
    +#define MAX77686_RTC_UPDATE_DELAY 16000

    enum {
    RTC_SEC = 0,
    @@ -130,7 +130,8 @@ static int max77686_rtc_update(struct max77686_rtc_info *info,
    __func__, ret, data);
    else {
    /* Minimum 16ms delay required before RTC update. */
    - msleep(MAX77686_RTC_UPDATE_DELAY);
    + usleep_range(MAX77686_RTC_UPDATE_DELAY,
    + MAX77686_RTC_UPDATE_DELAY * 2);
    }

    return ret;
    --
    2.5.0
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