From: Ian Abbott Date: Wed, 6 Nov 2013 20:45:59 +0000 (+0000) Subject: staging: comedi: s626: fix value written by s626_set_dac() X-Git-Tag: v3.13-rc2~16^2~14 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=3de00ee4ce6a61ce7b72fd50a8af47957a7b53a8;p=kernel%2Fkernel-generic.git 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 Reported-by: Dan Carpenter Cc: Dan Carpenter Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c index 6815cfe..b486099 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;