[PATCH 23/48] staging: comedi: addi_apci_3xx: use comedi_timeout()

[H Hartley Sweeten]

Use comedi_timeout() to wait for the analog input and output end-of-
conversions.

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 <hswee...@visionengravers.com>
Cc: Ian Abbott <abbo...@mev.co.uk>
Cc: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/staging/comedi/drivers/addi_apci_3xxx.c | 44 ++++++++++++++++++++-----
 1 file changed, 35 insertions(+), 9 deletions(-)

diff --git a/drivers/staging/comedi/drivers/addi_apci_3xxx.c 
b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
index ceadf8e..88d14a9 100644
--- a/drivers/staging/comedi/drivers/addi_apci_3xxx.c
+++ b/drivers/staging/comedi/drivers/addi_apci_3xxx.c
@@ -434,13 +434,26 @@ static int apci3xxx_ai_setup(struct comedi_device *dev, 
unsigned int chanspec)
        return 0;
 }
 
+static int apci3xxx_ai_eoc(struct comedi_device *dev,
+                          struct comedi_subdevice *s,
+                          struct comedi_insn *insn,
+                          unsigned long context)
+{
+       struct apci3xxx_private *devpriv = dev->private;
+       unsigned int status;
+
+       status = readl(devpriv->mmio + 20);
+       if (status & 0x1)
+               return 0;
+       return -EBUSY;
+}
+
 static int apci3xxx_ai_insn_read(struct comedi_device *dev,
                                 struct comedi_subdevice *s,
                                 struct comedi_insn *insn,
                                 unsigned int *data)
 {
        struct apci3xxx_private *devpriv = dev->private;
-       unsigned int val;
        int ret;
        int i;
 
@@ -453,10 +466,9 @@ static int apci3xxx_ai_insn_read(struct comedi_device *dev,
                writel(0x80000, devpriv->mmio + 8);
 
                /* Wait the EOS */
-               do {
-                       val = readl(devpriv->mmio + 20);
-                       val &= 0x1;
-               } while (!val);
+               ret = comedi_timeout(dev, s, insn, apci3xxx_ai_eoc, 0);
+               if (ret)
+                       return ret;
 
                /* Read the analog value */
                data[i] = readl(devpriv->mmio + 28);
@@ -622,6 +634,20 @@ static int apci3xxx_ai_cancel(struct comedi_device *dev,
        return 0;
 }
 
+static int apci3xxx_ao_eoc(struct comedi_device *dev,
+                          struct comedi_subdevice *s,
+                          struct comedi_insn *insn,
+                          unsigned long context)
+{
+       struct apci3xxx_private *devpriv = dev->private;
+       unsigned int status;
+
+       status = readl(devpriv->mmio + 96);
+       if (status & 0x100)
+               return 0;
+       return -EBUSY;
+}
+
 static int apci3xxx_ao_insn_write(struct comedi_device *dev,
                                  struct comedi_subdevice *s,
                                  struct comedi_insn *insn,
@@ -630,7 +656,7 @@ static int apci3xxx_ao_insn_write(struct comedi_device *dev,
        struct apci3xxx_private *devpriv = dev->private;
        unsigned int chan = CR_CHAN(insn->chanspec);
        unsigned int range = CR_RANGE(insn->chanspec);
-       unsigned int status;
+       int ret;
        int i;
 
        for (i = 0; i < insn->n; i++) {
@@ -641,9 +667,9 @@ static int apci3xxx_ao_insn_write(struct comedi_device *dev,
                writel((data[i] << 8) | chan, devpriv->mmio + 100);
 
                /* Wait the end of transfer */
-               do {
-                       status = readl(devpriv->mmio + 96);
-               } while ((status & 0x100) != 0x100);
+               ret = comedi_timeout(dev, s, insn, apci3xxx_ao_eoc, 0);
+               if (ret)
+                       return ret;
        }
 
        return insn->n;
-- 
1.8.5.2

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