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| author | Scott Valentine <svalentine@concentris-systems.com> | 2009-11-11 14:26:49 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-11-12 07:25:59 -0800 |
| commit | bcb3a1676b87effbdeffe8da5c44f63433d158d9 (patch) | |
| tree | 179eaa6692cad02a1e2b4c15a6919061aa06dd8d /drivers/rtc | |
| parent | 61df33370c52633b47d794f5e024eb15ca9a2efe (diff) | |
| download | linux-bcb3a1676b87effbdeffe8da5c44f63433d158d9.tar.gz linux-bcb3a1676b87effbdeffe8da5c44f63433d158d9.tar.bz2 linux-bcb3a1676b87effbdeffe8da5c44f63433d158d9.zip | |
rtc: v3020: fix v3020_mmio_read_bit()
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>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rtc')
| -rw-r--r-- | drivers/rtc/rtc-v3020.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/rtc/rtc-v3020.c b/drivers/rtc/rtc-v3020.c index ad164056feb6..423cd5a30b10 100644 --- a/drivers/rtc/rtc-v3020.c +++ b/drivers/rtc/rtc-v3020.c @@ -96,7 +96,7 @@ static void v3020_mmio_write_bit(struct v3020 *chip, unsigned char bit) 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 = { |