Use comedi_timeout() to wait for the analog input end-of-conversion.
This prevents a deadlock condition that could occur by providing a
timeout in case the end-of-conversion does not happen.
Signed-off-by: H Hartley Sweeten <hsweeten@xxxxxxxxxxxxxxxxxxx>
Cc: Ian Abbott <abbotti@xxxxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/staging/comedi/drivers/s626.c | 20 ++++++++++++++++++--
1 file changed, 18 insertions(+), 2 deletions(-)
diff --git a/drivers/staging/comedi/drivers/s626.c b/drivers/staging/comedi/drivers/s626.c
index 9e711ee..5ba4b4a 100644
--- a/drivers/staging/comedi/drivers/s626.c
+++ b/drivers/staging/comedi/drivers/s626.c
@@ -1846,6 +1846,20 @@ static int s626_ai_rinsn(struct comedi_device *dev,
}
#endif
+static int s626_ai_eoc(struct comedi_device *dev,
+ struct comedi_subdevice *s,
+ struct comedi_insn *insn,
+ unsigned long context)
+{
+ struct s626_private *devpriv = dev->private;
+ unsigned int status;
+
+ status = readl(devpriv->mmio + S626_P_PSR);
+ if (status & S626_PSR_GPIO2)
+ return 0;
+ return -EBUSY;
+}
+
static int s626_ai_insn_read(struct comedi_device *dev,
struct comedi_subdevice *s,
struct comedi_insn *insn, unsigned int *data)
@@ -1856,6 +1870,7 @@ static int s626_ai_insn_read(struct comedi_device *dev,
uint16_t adc_spec = 0;
uint32_t gpio_image;
uint32_t tmp;
+ int ret;
int n;
/*
@@ -1897,8 +1912,9 @@ static int s626_ai_insn_read(struct comedi_device *dev,
*/
/* Wait for ADC done */
- while (!(readl(devpriv->mmio + S626_P_PSR) & S626_PSR_GPIO2))
- ;
+ ret = comedi_timeout(dev, s, insn, s626_ai_eoc, 0);
+ if (ret)
+ return ret;
/* Fetch ADC data */
if (n != 0) {
--
1.8.5.2
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