[PATCH 07/14] staging: comedi: me4000: Fix endian problem for AI command data

Ian Abbott abbotti at mev.co.uk
Tue Feb 23 14:30:48 UTC 2021


The analog input subdevice supports Comedi asynchronous commands that
use Comedi's 16-bit sample format.  However, the calls to
`comedi_buf_write_samples()` are passing the address of a 32-bit integer
variable.  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 variable
holding the sample value to `unsigned short`.

Fixes: de88924f67d ("staging: comedi: me4000: use comedi_buf_write_samples()")
Cc: <stable at vger.kernel.org> # 3.19+
Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
 drivers/staging/comedi/drivers/me4000.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/me4000.c b/drivers/staging/comedi/drivers/me4000.c
index 726e40dc17b6..0d3d4cafce2e 100644
--- a/drivers/staging/comedi/drivers/me4000.c
+++ b/drivers/staging/comedi/drivers/me4000.c
@@ -924,7 +924,7 @@ static irqreturn_t me4000_ai_isr(int irq, void *dev_id)
 	struct comedi_subdevice *s = dev->read_subdev;
 	int i;
 	int c = 0;
-	unsigned int lval;
+	unsigned short lval;
 
 	if (!dev->attached)
 		return IRQ_NONE;
-- 
2.30.0



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