staging: comedi: s526: don't dereference insn->data pointer

The comedi_insn 'data' pointer is a __user pointer that is
passed into the kernel using an ioctl. The comedi core copies
this data to kernel space in do_insnlist_ioctl() and then
passes that kernel data to the drivers as a separate parameter.
The drivers never need to access the data through the insn->data
pointer.

This fixes a number of sparse warnings about:

  warning: dereference of noderef expression

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/staging/comedi/drivers/s526.c b/drivers/staging/comedi/drivers/s526.c
index c89bd6c..43f5c7d 100644 (file)
--- a/drivers/staging/comedi/drivers/s526.c
+++ b/drivers/staging/comedi/drivers/s526.c
@@ -256,14 +256,13 @@ static int s526_gpct_insn_config(struct comedi_device *dev,
                                                subdev_channel); */
 
        for (i = 0; i < MAX_GPCT_CONFIG_DATA; i++) {
-               devpriv->s526_gpct_config[subdev_channel].data[i] =
-                   insn->data[i];
-/* printk("data[%d]=%x\n", i, insn->data[i]); */
+               devpriv->s526_gpct_config[subdev_channel].data[i] = data[i];
+/* printk("data[%d]=%x\n", i, data[i]); */
        }
 
        /*  Check what type of Counter the user requested, data[0] contains */
        /*  the Application type */
-       switch (insn->data[0]) {
+       switch (data[0]) {
        case INSN_CONFIG_GPCT_QUADRATURE_ENCODER:
                /*
                   data[0]: Application Type
@@ -307,7 +306,7 @@ static int s526_gpct_insn_config(struct comedi_device *dev,
 
 #if 1
                /*  Set Counter Mode Register */
-               cmReg.value = insn->data[1] & 0xFFFF;
+               cmReg.value = data[1] & 0xFFFF;
 
 /* printk("s526: Counter Mode register=%x\n", cmReg.value); */
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
@@ -325,39 +324,39 @@ static int s526_gpct_insn_config(struct comedi_device *dev,
                cmReg.reg.countDirCtrl = 0;
 
                /*  data[1] contains GPCT_X1, GPCT_X2 or GPCT_X4 */
-               if (insn->data[1] == GPCT_X2)
+               if (data[1] == GPCT_X2)
                        cmReg.reg.clockSource = 1;
-               else if (insn->data[1] == GPCT_X4)
+               else if (data[1] == GPCT_X4)
                        cmReg.reg.clockSource = 2;
                else
                        cmReg.reg.clockSource = 0;
 
                /*  When to take into account the indexpulse: */
-               /*if (insn->data[2] == GPCT_IndexPhaseLowLow) {
-               } else if (insn->data[2] == GPCT_IndexPhaseLowHigh) {
-               } else if (insn->data[2] == GPCT_IndexPhaseHighLow) {
-               } else if (insn->data[2] == GPCT_IndexPhaseHighHigh) {
+               /*if (data[2] == GPCT_IndexPhaseLowLow) {
+               } else if (data[2] == GPCT_IndexPhaseLowHigh) {
+               } else if (data[2] == GPCT_IndexPhaseHighLow) {
+               } else if (data[2] == GPCT_IndexPhaseHighHigh) {
                }*/
                /*  Take into account the index pulse? */
-               if (insn->data[3] == GPCT_RESET_COUNTER_ON_INDEX)
+               if (data[3] == GPCT_RESET_COUNTER_ON_INDEX)
                        /*  Auto load with INDEX^ */
                        cmReg.reg.autoLoadResetRcap = 4;
 
                /*  Set Counter Mode Register */
-               cmReg.value = (short)(insn->data[1] & 0xFFFF);
+               cmReg.value = (short)(data[1] & 0xFFFF);
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
 
                /*  Load the pre-load register high word */
-               value = (short)((insn->data[2] >> 16) & 0xFFFF);
+               value = (short)((data[2] >> 16) & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0H, subdev_channel));
 
                /*  Load the pre-load register low word */
-               value = (short)(insn->data[2] & 0xFFFF);
+               value = (short)(data[2] & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0L, subdev_channel));
 
                /*  Write the Counter Control Register */
-               if (insn->data[3] != 0) {
-                       value = (short)(insn->data[3] & 0xFFFF);
+               if (data[3] != 0) {
+                       value = (short)(data[3] & 0xFFFF);
                        outw(value, ADDR_CHAN_REG(REG_C0C, subdev_channel));
                }
                /*  Reset the counter if it is software preload */
@@ -383,34 +382,34 @@ static int s526_gpct_insn_config(struct comedi_device *dev,
                    SinglePulseGeneration;
 
                /*  Set Counter Mode Register */
-               cmReg.value = (short)(insn->data[1] & 0xFFFF);
+               cmReg.value = (short)(data[1] & 0xFFFF);
                cmReg.reg.preloadRegSel = 0;    /*  PR0 */
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
 
                /*  Load the pre-load register 0 high word */
-               value = (short)((insn->data[2] >> 16) & 0xFFFF);
+               value = (short)((data[2] >> 16) & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0H, subdev_channel));
 
                /*  Load the pre-load register 0 low word */
-               value = (short)(insn->data[2] & 0xFFFF);
+               value = (short)(data[2] & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0L, subdev_channel));
 
                /*  Set Counter Mode Register */
-               cmReg.value = (short)(insn->data[1] & 0xFFFF);
+               cmReg.value = (short)(data[1] & 0xFFFF);
                cmReg.reg.preloadRegSel = 1;    /*  PR1 */
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
 
                /*  Load the pre-load register 1 high word */
-               value = (short)((insn->data[3] >> 16) & 0xFFFF);
+               value = (short)((data[3] >> 16) & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0H, subdev_channel));
 
                /*  Load the pre-load register 1 low word */
-               value = (short)(insn->data[3] & 0xFFFF);
+               value = (short)(data[3] & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0L, subdev_channel));
 
                /*  Write the Counter Control Register */
-               if (insn->data[4] != 0) {
-                       value = (short)(insn->data[4] & 0xFFFF);
+               if (data[4] != 0) {
+                       value = (short)(data[4] & 0xFFFF);
                        outw(value, ADDR_CHAN_REG(REG_C0C, subdev_channel));
                }
                break;
@@ -428,34 +427,34 @@ static int s526_gpct_insn_config(struct comedi_device *dev,
                    PulseTrainGeneration;
 
                /*  Set Counter Mode Register */
-               cmReg.value = (short)(insn->data[1] & 0xFFFF);
+               cmReg.value = (short)(data[1] & 0xFFFF);
                cmReg.reg.preloadRegSel = 0;    /*  PR0 */
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
 
                /*  Load the pre-load register 0 high word */
-               value = (short)((insn->data[2] >> 16) & 0xFFFF);
+               value = (short)((data[2] >> 16) & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0H, subdev_channel));
 
                /*  Load the pre-load register 0 low word */
-               value = (short)(insn->data[2] & 0xFFFF);
+               value = (short)(data[2] & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0L, subdev_channel));
 
                /*  Set Counter Mode Register */
-               cmReg.value = (short)(insn->data[1] & 0xFFFF);
+               cmReg.value = (short)(data[1] & 0xFFFF);
                cmReg.reg.preloadRegSel = 1;    /*  PR1 */
                outw(cmReg.value, ADDR_CHAN_REG(REG_C0M, subdev_channel));
 
                /*  Load the pre-load register 1 high word */
-               value = (short)((insn->data[3] >> 16) & 0xFFFF);
+               value = (short)((data[3] >> 16) & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0H, subdev_channel));
 
                /*  Load the pre-load register 1 low word */
-               value = (short)(insn->data[3] & 0xFFFF);
+               value = (short)(data[3] & 0xFFFF);
                outw(value, ADDR_CHAN_REG(REG_C0L, subdev_channel));
 
                /*  Write the Counter Control Register */
-               if (insn->data[4] != 0) {
-                       value = (short)(insn->data[4] & 0xFFFF);
+               if (data[4] != 0) {
+                       value = (short)(data[4] & 0xFFFF);
                        outw(value, ADDR_CHAN_REG(REG_C0C, subdev_channel));
                }
                break;
@@ -505,14 +504,14 @@ static int s526_gpct_winsn(struct comedi_device *dev,
                   pulse frequency on the selected source
                 */
                printk(KERN_INFO "S526: INSN_WRITE: PTG\n");
-               if ((insn->data[1] > insn->data[0]) && (insn->data[0] > 0)) {
+               if ((data[1] > data[0]) && (data[0] > 0)) {
                        (devpriv->s526_gpct_config[subdev_channel]).data[0] =
-                           insn->data[0];
+                           data[0];
                        (devpriv->s526_gpct_config[subdev_channel]).data[1] =
-                           insn->data[1];
+                           data[1];
                } else {
                        printk(KERN_ERR "s526: INSN_WRITE: PTG: Problem with Pulse params -> %d %d\n",
-                               insn->data[0], insn->data[1]);
+                               data[0], data[1]);
                        return -EINVAL;
                }