diff options
| author | Ian Abbott <abbotti@mev.co.uk> | 2013-11-06 20:45:59 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-11-25 09:09:07 -0800 |
| commit | 3de00ee4ce6a61ce7b72fd50a8af47957a7b53a8 (patch) | |
| tree | b4551fd38994831f3a73db2fd5eb48908ea2e8ce | |
| parent | 9382c06e2d192adec090fb09ff0b699e951f88e1 (diff) | |
staging: comedi: s626: fix value written by s626_set_dac()
I broke `s626_set_dac()` by changing the type of the `dacdata` parameter
from `short` to `unsigned short`. It's actually designed to take a
signed value in the range -0x1fff to +0x2000 although values above
0x1fff get clamped to 0x1fff. (We could change the `maxdata` value to
0x1ffe to avoid the clamping, but `maxdata` values are usually a power
of 2 minus 1.) The bug results in all negative values passed to the
function being changed to +0x1fff by the clamp. Change the parameter
type to `int16_t` to fix the problem.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/staging/comedi/drivers/s626.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c index 6815cfe2664e..b486099b543d 100644 --- a/drivers/staging/comedi/drivers/s626.c +++ b/drivers/staging/comedi/drivers/s626.c @@ -494,7 +494,7 @@ static void s626_send_dac(struct comedi_device *dev, uint32_t val) * Private helper function: Write setpoint to an application DAC channel. */ static void s626_set_dac(struct comedi_device *dev, uint16_t chan, - unsigned short dacdata) + int16_t dacdata) { struct s626_private *devpriv = dev->private; uint16_t signmask; |