amplc_dio200: Protect access to counter subdevices with a spin lock.

diff --git a/comedi/drivers/amplc_dio200.c b/comedi/drivers/amplc_dio200.c
index 228291a569d8ba5604ac74b220c25425af5ec090..8f54b264abf44dc31f410290e07d1f0ada6b1e9e 100644 (file)
--- a/comedi/drivers/amplc_dio200.c
+++ b/comedi/drivers/amplc_dio200.c
@@ -454,6 +454,7 @@ typedef struct {
        int has_clk_gat_sce;
        unsigned clock_src[3];  /* Current clock sources */
        unsigned gate_src[3];   /* Current gate sources */
+       spinlock_t spinlock;
 } dio200_subdev_8254;
 
 typedef struct {
@@ -1038,8 +1039,11 @@ dio200_subdev_8254_read(comedi_device * dev, comedi_subdevice * s,
 {
        dio200_subdev_8254 *subpriv = s->private;
        int chan = CR_CHAN(insn->chanspec);
+       unsigned long flags;
 
+       comedi_spin_lock_irqsave(&subpriv->spinlock, flags);
        data[0] = i8254_read(subpriv->iobase, 0, chan);
+       comedi_spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
        return 1;
 }
@@ -1053,8 +1057,11 @@ dio200_subdev_8254_write(comedi_device * dev, comedi_subdevice * s,
 {
        dio200_subdev_8254 *subpriv = s->private;
        int chan = CR_CHAN(insn->chanspec);
+       unsigned long flags;
 
+       comedi_spin_lock_irqsave(&subpriv->spinlock, flags);
        i8254_write(subpriv->iobase, 0, chan, data[0]);
+       comedi_spin_unlock_irqrestore(&subpriv->spinlock, flags);
 
        return 1;
 }
@@ -1146,14 +1153,16 @@ dio200_subdev_8254_config(comedi_device * dev, comedi_subdevice * s,
        comedi_insn * insn, lsampl_t * data)
 {
        dio200_subdev_8254 *subpriv = s->private;
-       int ret;
+       int ret = 0;
        int chan = CR_CHAN(insn->chanspec);
+       unsigned long flags;
 
+       comedi_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);
@@ -1161,30 +1170,35 @@ dio200_subdev_8254_config(comedi_device * dev, 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;
+       comedi_spin_unlock_irqrestore(&subpriv->spinlock, flags);
+       return ret < 0 ? ret : insn->n;
 }
 
 /*
@@ -1216,6 +1230,7 @@ dio200_subdev_8254_init(comedi_device * dev, 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) {