[PATCH 04/14] staging: comedi: das6402: Fix endian problem for AI command data

Ian Abbott abbotti at mev.co.uk
Tue Feb 23 14:30:45 UTC 2021


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
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: d1d24cb65ee3 ("staging: comedi: das6402: read analog input samples in interrupt handler")
Cc: <stable at vger.kernel.org> # 3.19+
Signed-off-by: Ian Abbott <abbotti at mev.co.uk>
---
 drivers/staging/comedi/drivers/das6402.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/staging/comedi/drivers/das6402.c b/drivers/staging/comedi/drivers/das6402.c
index 04e224f8b779..96f4107b8054 100644
--- a/drivers/staging/comedi/drivers/das6402.c
+++ b/drivers/staging/comedi/drivers/das6402.c
@@ -186,7 +186,7 @@ static irqreturn_t das6402_interrupt(int irq, void *d)
 	if (status & DAS6402_STATUS_FFULL) {
 		async->events |= COMEDI_CB_OVERFLOW;
 	} else if (status & DAS6402_STATUS_FFNE) {
-		unsigned int val;
+		unsigned short val;
 
 		val = das6402_ai_read_sample(dev, s);
 		comedi_buf_write_samples(s, &val, 1);
-- 
2.30.0



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