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staging: comedi: pcl818: Fix endian problem for AI command data

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commit 148e34fd33d53740642db523724226de14ee5281 upstream.

The analog input subdevice supports Comedi asynchronous commands that
use Comedi's 16-bit sample format.  However, the call to
`comedi_buf_write_samples()` is passing the address of a 32-bit integer
parameter.  On bigendian machines, this will copy 2 bytes from the wrong
end of the 32-bit value.  Fix it by changing the type of the parameter
holding the sample value to `unsigned short`.

[Note: the bug was introduced in commit edf4537bcbf5 ("staging: comedi:
pcl818: use comedi_buf_write_samples()") but the patch applies better to
commit d615416de615 ("staging: comedi: pcl818: introduce
pcl818_ai_write_sample()").]

Fixes: d615416de615 ("staging: comedi: pcl818: introduce pcl818_ai_write_sample()")
Cc: <stable@vger.kernel.org> # 4.0+
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Link: https://lore.kernel.org/r/20210223143055.257402-10-abbotti@mev.co.uk
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Ian Abbott 2021-02-23 14:30:50 +00:00 committed by Greg Kroah-Hartman
parent c5916897a6
commit c3c1defad2
1 changed files with 1 additions and 1 deletions
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2
drivers/staging/comedi/drivers/pcl818.c
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@ -423,7 +423,7 @@ static int pcl818_ai_eoc(struct comedi_device *dev,
static bool pcl818_ai_write_sample(struct comedi_device *dev,
struct comedi_subdevice *s,
unsigned int chan, unsigned int val)
unsigned int chan, unsigned short val)
{
struct pcl818_private *devpriv = dev->private;
struct comedi_cmd *cmd = &s->async->cmd;