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authorIan Abbott <abbotti@mev.co.uk>2013-11-06 20:45:59 +0000
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-11-25 09:09:07 -0800
commit3de00ee4ce6a61ce7b72fd50a8af47957a7b53a8 (patch)
treeb4551fd38994831f3a73db2fd5eb48908ea2e8ce /drivers
parent9382c06e2d192adec090fb09ff0b699e951f88e1 (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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/comedi/drivers/s626.c2
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;