[PATCH 3.16 016/305] staging: comedi: quatech_daqp_cs: fix bug in daqp_ao_insn_write()

From: Ben Hutchings
Date: Sun Feb 03 2019 - 09:00:20 EST


3.16.63-rc1 review patch. If anyone has any objections, please let me know.

------------------

From: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>

commit e024181b02ed6b833358bede3f2d0c52cb5fb6bc upstream.

The comedi core expects (*insn_write) functions to write insn->n values
to the hardware and return the number of values written.

Currently, this function only writes the first value. Fix it to work
like the core expects.

Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Reviewed-by: Ian Abbott <abbotti@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/quatech_daqp_cs.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/staging/comedi/drivers/quatech_daqp_cs.c
+++ b/drivers/staging/comedi/drivers/quatech_daqp_cs.c
@@ -640,7 +640,6 @@ static int daqp_ao_insn_write(struct com
{
struct daqp_private *devpriv = dev->private;
unsigned int chan = CR_CHAN(insn->chanspec);
- unsigned int val;
int i;

if (devpriv->stop)
@@ -650,7 +649,8 @@ static int daqp_ao_insn_write(struct com
outb(0, dev->iobase + DAQP_AUX);

for (i = 0; i > insn->n; i++) {
- val = data[0];
+ unsigned val = data[i];
+
val &= 0x0fff;
val ^= 0x0800; /* Flip the sign */
val |= (chan << 12);