lkml.org 
[lkml]   [2009]   [Dec]   [6]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[033/119] rtc: v3020: fix v3020_mmio_read_bit()
    2.6.31-stable review patch.  If anyone has any objections, please let us know.

    ------------------
    From: Scott Valentine <svalentine@concentris-systems.com>

    commit bcb3a1676b87effbdeffe8da5c44f63433d158d9 upstream.

    v3020_mmio_read_bit() always returns 0 when left_shift > 7.

    v3020_mmio_read_bit()'s return type is (unsigned char). The code returns
    a value masked by (1 << left_shift) that is casted to the return type. If
    left_shift is larger than 7, the cast will always result in a 0 return
    value. The problem was discovered with left_shift = 16, and the included
    patch corrects the problem.

    The bug was introduced in the last (Apr 3 2009) commit of the file, kernel
    versions 2.6.30 and later.

    Cc: Alessandro Zummo <a.zummo@towertech.it>
    Cc: Paul Gortmaker <p_gortmaker@yahoo.com>
    Cc: Raphael Assenat <raph@8d.com>
    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@suse.de>

    ---
    drivers/rtc/rtc-v3020.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/drivers/rtc/rtc-v3020.c
    +++ b/drivers/rtc/rtc-v3020.c
    @@ -96,7 +96,7 @@ static void v3020_mmio_write_bit(struct

    static unsigned char v3020_mmio_read_bit(struct v3020 *chip)
    {
    - return readl(chip->ioaddress) & (1 << chip->leftshift);
    + return !!(readl(chip->ioaddress) & (1 << chip->leftshift));
    }

    static struct v3020_chip_ops v3020_mmio_ops = {



    \
     
     \ /
      Last update: 2009-12-07 01:41    [W:0.022 / U:59.204 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site