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>
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@ -494,7 +494,7 @@ static void s626_send_dac(struct comedi_device *dev, uint32_t val)
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* Private helper function: Write setpoint to an application DAC channel.
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*/
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static void s626_set_dac(struct comedi_device *dev, uint16_t chan,
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unsigned short dacdata)
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int16_t dacdata)
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{
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struct s626_private *devpriv = dev->private;
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uint16_t signmask;
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