fixes to make interrupt handling more robust

diff --git a/comedi/drivers/das16.c b/comedi/drivers/das16.c
index 129a6649109e5c701cd95baf3583fa5a27c9cd51..cefe45890450c3ca18076e4ecc1d6bfed00b9606 100644 (file)
--- a/comedi/drivers/das16.c
+++ b/comedi/drivers/das16.c
@@ -699,14 +699,13 @@ struct das16_private_struct {
        unsigned int    ai_unipolar;    // unipolar flag
        unsigned int    ai_singleended; // single ended flag
        unsigned int    clockbase;      // master clock speed in ns
-       unsigned int    control_state;  // dma, interrupt and trigger control bits
-       unsigned int    adc_count;      // number of samples remaining
-       unsigned int    do_bits;        // digital output bits
+       volatile unsigned int   control_state;  // dma, interrupt and trigger control bits
+       volatile unsigned int   adc_count;      // number of samples remaining
        unsigned int divisor1;  // divisor dividing master clock to get conversion frequency
        unsigned int divisor2;  // divisor dividing master clock to get conversion frequency
        unsigned int dma_chan;  // dma channel
        sampl_t *dma_buffer;
-       unsigned int dma_transfer_size; // number of bytes transfered per dma shot
+       volatile unsigned int dma_transfer_size;        // number of bytes transfered per dma shot
        // user-defined analog input and output ranges defined from config options
        comedi_lrange *user_ai_range_table;
        comedi_lrange *user_ao_range_table;
@@ -998,30 +997,34 @@ static int das16_ai_rinsn(comedi_device *dev,comedi_subdevice *s,comedi_insn *in
        /* set multiplexer */
        chan = CR_CHAN(insn->chanspec);
        chan |= CR_CHAN(insn->chanspec) << 4;
-       outb(chan,dev->iobase+DAS16_MUX);
+       outb(chan, dev->iobase + DAS16_MUX);
 
        /* set gain */
-       if(thisboard->ai_pg != das16_pg_none){
+       if(thisboard->ai_pg != das16_pg_none)
+       {
                range = CR_RANGE(insn->chanspec);
                outb((das16_gainlists[thisboard->ai_pg])[range],
                        dev->iobase+DAS16_GAIN);
        }
 
-       for(n=0;n<insn->n;n++){
+       for(n = 0; n < insn->n; n++)
+       {
                /* trigger conversion */
-               outb_p(0,dev->iobase+DAS16_TRIG);
+               outb_p(0, dev->iobase + DAS16_TRIG);
 
-               for(i=0;i<DAS16_TIMEOUT;i++){
+               for(i = 0; i < DAS16_TIMEOUT; i++)
+               {
                        if(!(inb(dev->iobase + DAS16_STATUS) & BUSY))
                                break;
                }
-               if(i==DAS16_TIMEOUT){
+               if(i == DAS16_TIMEOUT)
+               {
                        rt_printk("das16: timeout\n");
                        return -ETIME;
                }
                msb = inb(dev->iobase + DAS16_AI_MSB);
                lsb = inb(dev->iobase + DAS16_AI_LSB);
-               if(thisboard->ai_nbits==12){
+               if(thisboard->ai_nbits == 12){
                        data[n] = ((lsb >> 4) & 0xf) | (msb << 4);
                }else{
                        data[n] = lsb | (msb << 8);
@@ -1035,7 +1038,7 @@ static int das16_di_rbits(comedi_device *dev,comedi_subdevice *s,comedi_insn *in
 {
        lsampl_t bits;
 
-       bits = inb(dev->iobase+DAS16_DIO) & 0xf;
+       bits = inb(dev->iobase + DAS16_DIO) & 0xf;
        data[1] = bits;
        data[0] = 0;
 
@@ -1048,15 +1051,15 @@ static int das16_do_wbits(comedi_device *dev,comedi_subdevice *s,comedi_insn *in
 
        // only set bits that have been masked
        data[0] &= 0xf;
-       wbits = devpriv->do_bits;
+       wbits = s->state;
        // zero bits that have been masked
        wbits &= ~data[0];
        // set masked bits
        wbits |= data[0] & data[1];
-       devpriv->do_bits = wbits;
+       s->state = wbits;
        data[1] = wbits;
 
-       outb(devpriv->do_bits, dev->iobase + DAS16_DIO);
+       outb(s->state, dev->iobase + DAS16_DIO);
 
        return 2;
 }
@@ -1067,24 +1070,21 @@ static int das16_ao_winsn(comedi_device *dev,comedi_subdevice *s,comedi_insn *in
        int lsb,msb;
        int chan;
 
-       chan=CR_CHAN(insn->chanspec);
+       chan = CR_CHAN(insn->chanspec);
 
-       for(i=0;i<insn->n;i++){
-               if(thisboard->ao_nbits==12){
-                       lsb=(data[i]<<4)&0xff;
-                       msb=(data[i]>>4)&0xff;
-               }else{
-                       lsb=data[i]&0xff;
-                       msb=(data[i]>>8)&0xff;
+       for(i = 0; i < insn->n; i++)
+       {
+               if(thisboard->ao_nbits == 12)
+               {
+                       lsb = (data[i] << 4) & 0xff;
+                       msb = (data[i] >> 4) & 0xff;
+               }else
+               {
+                       lsb = data[i] & 0xff;
+                       msb = (data[i] >> 8) & 0xff;
                }
-
-#if 0
-               outb(lsb,dev->iobase+devpriv->ao_offset_lsb[chan]);
-               outb(msb,dev->iobase+devpriv->ao_offset_msb[chan]);
-#else
                outb(lsb,dev->iobase+DAS16_AO_LSB(chan));
                outb(msb,dev->iobase+DAS16_AO_MSB(chan));
-#endif
        }
 
        return i;
@@ -1107,7 +1107,7 @@ static void das16_interrupt(int irq, void *d, struct pt_regs *regs)
                comedi_error(dev, "premature interrupt");
                return;
        }
-       // initialize async here to make sure s is not NULL
+       // initialize async here to make sure it is not NULL
        async = s->async;
        async->events = 0;
 
@@ -1135,6 +1135,12 @@ static void das16_interrupt(int irq, void *d, struct pt_regs *regs)
         * the stop_src is set to external triggering.
         */
        residue = get_dma_residue(devpriv->dma_chan) / sample_size;
+       if(residue > max_points)
+       {
+               comedi_error(dev, "residue > max_points!\n");
+               async->events |= COMEDI_CB_ERROR;
+               residue = max_points;
+       }
        num_points = max_points - residue;
        if(devpriv->adc_count < num_points &&
                async->cmd.stop_src == TRIG_COUNT)
@@ -1142,7 +1148,7 @@ static void das16_interrupt(int irq, void *d, struct pt_regs *regs)
 
        // figure out how many points will be stored next time
        leftover = 0;
-       if(async->cmd.stop_src != TRIG_COUNT)
+       if(async->cmd.stop_src == TRIG_NONE)
        {
                leftover = devpriv->dma_transfer_size / sample_size;
        }else if(devpriv->adc_count > num_points)
@@ -1151,12 +1157,6 @@ static void das16_interrupt(int irq, void *d, struct pt_regs *regs)
                if(leftover > max_points)
                        leftover = max_points;
        }
-       /* there should only be a residue if collection was stopped by having
-        * the stop_src set to an external trigger, in which case there
-        * will be no more data
-        */
-       if(residue)
-               leftover = 0;
 
        for(i = 0; i < num_points; i++)
        {
@@ -1168,9 +1168,12 @@ static void das16_interrupt(int irq, void *d, struct pt_regs *regs)
                if(devpriv->adc_count > 0) devpriv->adc_count--;
        }
        // re-enable  dma
-       set_dma_addr(devpriv->dma_chan, virt_to_bus(devpriv->dma_buffer));
-       set_dma_count(devpriv->dma_chan, leftover * sample_size);
-       enable_dma(devpriv->dma_chan);
+       if(leftover)
+       {
+               set_dma_addr(devpriv->dma_chan, virt_to_bus(devpriv->dma_buffer));
+               set_dma_count(devpriv->dma_chan, leftover * sample_size);
+               enable_dma(devpriv->dma_chan);
+       }
        release_dma_lock(flags);
 
        async->events |= COMEDI_CB_BLOCK;
@@ -1357,12 +1360,12 @@ static int das16_attach(comedi_device *dev, comedi_devconfig *it)
        }
 
        /* now for the irq */
-       irq=it->options[1];
+       irq = it->options[1];
        if(irq > 1 && irq < 8)
        {
-               if((ret=comedi_request_irq(irq,das16_interrupt,0,"das16",dev))<0)
+               if((ret=comedi_request_irq(irq, das16_interrupt, 0, "das16",dev)) < 0)
                        return ret;
-               dev->irq=irq;
+               dev->irq = irq;
                printk(" ( irq = %d )",irq);
        }else if(irq == 0){
                printk(" ( no irq )");
@@ -1504,6 +1507,8 @@ static int das16_attach(comedi_device *dev, comedi_devconfig *it)
                s->maxdata = 1;
                s->range_table = &range_digital;
                s->insn_bits = thisboard->do_;
+               // initialize digital output lines
+               outb(s->state, dev->iobase + DAS16_DIO);
        }else{
                s->type = COMEDI_SUBD_UNUSED;
        }
@@ -1518,9 +1523,7 @@ static int das16_attach(comedi_device *dev, comedi_devconfig *it)
        }
 
        das16_reset(dev);
-       // initialize digital output lines
-       outb(devpriv->do_bits, dev->iobase + DAS16_DIO);
-       /* set the interrupt level,enable pacer clock */
+       /* set the interrupt level */
        devpriv->control_state = DAS16_IRQ(dev->irq);
        outb(devpriv->control_state, dev->iobase + DAS16_CONTROL);