[PATCH 03/11] staging: comedi: pcmad: return errno if AI conversion times out
H Hartley Sweeten
hsweeten at visionengravers.com
Wed Jun 5 22:36:24 UTC 2013
Instead of returning invalid data, return -ETIME if the analog input
conversion times out.
Signed-off-by: H Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ian Abbott <abbotti at mev.co.uk>
Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
---
drivers/staging/comedi/drivers/pcmad.c | 22 +++++++++++++++++-----
1 file changed, 17 insertions(+), 5 deletions(-)
diff --git a/drivers/staging/comedi/drivers/pcmad.c b/drivers/staging/comedi/drivers/pcmad.c
index 79cc2e6..f64e75b 100644
--- a/drivers/staging/comedi/drivers/pcmad.c
+++ b/drivers/staging/comedi/drivers/pcmad.c
@@ -72,25 +72,37 @@ struct pcmad_priv_struct {
#define TIMEOUT 100
+static int pcmad_ai_wait_for_eoc(struct comedi_device *dev,
+ int timeout)
+{
+ int i;
+
+ for (i = 0; i < timeout; i++) {
+ if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
+ return 0;
+ }
+ return -ETIME;
+}
+
static int pcmad_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
{
const struct pcmad_board_struct *board = comedi_board(dev);
struct pcmad_priv_struct *devpriv = dev->private;
- int i;
int chan;
int n;
+ int ret;
chan = CR_CHAN(insn->chanspec);
for (n = 0; n < insn->n; n++) {
outb(chan, dev->iobase + PCMAD_CONVERT);
- for (i = 0; i < TIMEOUT; i++) {
- if ((inb(dev->iobase + PCMAD_STATUS) & 0x3) == 0x3)
- break;
- }
+ ret = pcmad_ai_wait_for_eoc(dev, TIMEOUT);
+ if (ret)
+ return ret;
+
data[n] = inb(dev->iobase + PCMAD_LSB);
data[n] |= (inb(dev->iobase + PCMAD_MSB) << 8);
--
1.8.1.4
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