1 files changed, 25 insertions, 10 deletions

diff --git a/drivers/staging/comedi/drivers/amplc_dio200.c b/drivers/staging/comedi/drivers/amplc_dio200.c
index 8eb67651486a..bf27617aa62d 100644
--- a/drivers/staging/comedi/drivers/amplc_dio200.c
+++ b/drivers/staging/comedi/drivers/amplc_dio200.c
@@ -460,6 +460,7 @@ struct dio200_subdev_8254 {
         int has_clk_gat_sce;
         unsigned clock_src[3];  /* Current clock sources */
         unsigned gate_src[3];   /* Current gate sources */
+        spinlock_t spinlock;
 };
 
 struct dio200_subdev_intr {
@@ -1042,8 +1043,11 @@ dio200_subdev_8254_read(struct comedi_device *dev, struct comedi_subdevice *s,
 {
         struct dio200_subdev_8254 *subpriv = s->private;
         int chan = CR_CHAN(insn->chanspec);
+        unsigned long flags;
 
+        spin_lock_irqsave(&subpriv->spinlock, flags);
         data[0] = i8254_read(subpriv->iobase, 0, chan);
+        spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
         return 1;
 }
@@ -1057,8 +1061,11 @@ dio200_subdev_8254_write(struct comedi_device *dev, struct comedi_subdevice *s,
 {
         struct dio200_subdev_8254 *subpriv = s->private;
         int chan = CR_CHAN(insn->chanspec);
+        unsigned long flags;
 
+        spin_lock_irqsave(&subpriv->spinlock, flags);
         i8254_write(subpriv->iobase, 0, chan, data[0]);
+        spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
         return 1;
 }
@@ -1151,14 +1158,16 @@ dio200_subdev_8254_config(struct comedi_device *dev, struct comedi_subdevice *s,
                           struct comedi_insn *insn, unsigned int *data)
 {
         struct dio200_subdev_8254 *subpriv = s->private;
-        int ret;
+        int ret = 0;
         int chan = CR_CHAN(insn->chanspec);
+        unsigned long flags;
 
+        spin_lock_irqsave(&subpriv->spinlock, flags);
         switch (data[0]) {
         case INSN_CONFIG_SET_COUNTER_MODE:
                 ret = i8254_set_mode(subpriv->iobase, 0, chan, data[1]);
                 if (ret < 0)
-                        return -EINVAL;
+                        ret = -EINVAL;
                 break;
         case INSN_CONFIG_8254_READ_STATUS:
                 data[1] = i8254_status(subpriv->iobase, 0, chan);
@@ -1166,30 +1175,35 @@ dio200_subdev_8254_config(struct comedi_device *dev, struct comedi_subdevice *s,
         case INSN_CONFIG_SET_GATE_SRC:
                 ret = dio200_set_gate_src(subpriv, chan, data[2]);
                 if (ret < 0)
-                        return -EINVAL;
+                        ret = -EINVAL;
                 break;
         case INSN_CONFIG_GET_GATE_SRC:
                 ret = dio200_get_gate_src(subpriv, chan);
-                if (ret < 0)
-                        return -EINVAL;
+                if (ret < 0) {
+                        ret = -EINVAL;
+                        break;
+                }
                 data[2] = ret;
                 break;
         case INSN_CONFIG_SET_CLOCK_SRC:
                 ret = dio200_set_clock_src(subpriv, chan, data[1]);
                 if (ret < 0)
-                        return -EINVAL;
+                        ret = -EINVAL;
                 break;
         case INSN_CONFIG_GET_CLOCK_SRC:
                 ret = dio200_get_clock_src(subpriv, chan, &data[2]);
-                if (ret < 0)
-                        return -EINVAL;
+                if (ret < 0) {
+                        ret = -EINVAL;
+                        break;
+                }
                 data[1] = ret;
                 break;
         default:
-                return -EINVAL;
+                ret = -EINVAL;
                 break;
         }
-        return insn->n;
+        spin_unlock_irqrestore(&subpriv->spinlock, flags);
+        return ret < 0 ? ret : insn->n;
 }
 
 /*
@@ -1222,6 +1236,7 @@ dio200_subdev_8254_init(struct comedi_device *dev, struct comedi_subdevice *s,
         s->insn_write = dio200_subdev_8254_write;
         s->insn_config = dio200_subdev_8254_config;
 
+        spin_lock_init(&subpriv->spinlock);
         subpriv->iobase = offset + iobase;
         subpriv->has_clk_gat_sce = has_clk_gat_sce;
         if (has_clk_gat_sce) {