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    Subject[ 085/127] drivers/rtc/rtc-rs5c348.c: fix hour decoding in 12-hour mode
    Date
    3.0-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Atsushi Nemoto <anemo@mba.ocn.ne.jp>

    commit 7dbfb315b2aaef0a115765946bf3026d074c33a7 upstream.

    Correct the offset by subtracting 20 from tm_hour before taking the
    modulo 12.

    [ "Why 20?" I hear you ask. Or at least I did.

    Here's the reason why: RS5C348_BIT_PM is 32, and is - stupidly -
    included in the RS5C348_HOURS_MASK define. So it's really subtracting
    out that bit to get "hour+12". But then because it does things modulo
    12, it needs to add the 12 in again afterwards anyway.

    This code is confused. It would be much clearer if RS5C348_HOURS_MASK
    just didn't include the RS5C348_BIT_PM bit at all, then it wouldn't
    need to do the silly subtract either.

    Whatever. It's all just math, the end result is the same. - Linus ]

    Reported-by: James Nute <newten82@gmail.com>
    Tested-by: James Nute <newten82@gmail.com>
    Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp>
    Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/rtc/rtc-rs5c348.c | 7 +++++--
    1 file changed, 5 insertions(+), 2 deletions(-)

    --- a/drivers/rtc/rtc-rs5c348.c
    +++ b/drivers/rtc/rtc-rs5c348.c
    @@ -121,9 +121,12 @@ rs5c348_rtc_read_time(struct device *dev
    tm->tm_min = bcd2bin(rxbuf[RS5C348_REG_MINS] & RS5C348_MINS_MASK);
    tm->tm_hour = bcd2bin(rxbuf[RS5C348_REG_HOURS] & RS5C348_HOURS_MASK);
    if (!pdata->rtc_24h) {
    - tm->tm_hour %= 12;
    - if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM)
    + if (rxbuf[RS5C348_REG_HOURS] & RS5C348_BIT_PM) {
    + tm->tm_hour -= 20;
    + tm->tm_hour %= 12;
    tm->tm_hour += 12;
    + } else
    + tm->tm_hour %= 12;
    }
    tm->tm_wday = bcd2bin(rxbuf[RS5C348_REG_WDAY] & RS5C348_WDAY_MASK);
    tm->tm_mday = bcd2bin(rxbuf[RS5C348_REG_DAY] & RS5C348_DAY_MASK);



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