making sure there are no races wrt ai_cmd_running status flag

diff --git a/comedi/drivers/cb_pcidas64.c b/comedi/drivers/cb_pcidas64.c
index 5a95ddfb47920fd445415fa139b73dd3bef5d704..ef36ed31e5ae8518b6fff1712e1d7457f4612148 100644 (file)
--- a/comedi/drivers/cb_pcidas64.c
+++ b/comedi/drivers/cb_pcidas64.c
@@ -369,6 +369,7 @@ enum i2c_addresses
 enum range_cal_i2c_contents
 {
        ADC_SRC_4020_MASK = 0x70,       // bits that set what source the adc converter measures
+       BNC_TRIG_THRESHOLD_0V_BIT = 0x80,       // make bnc trig/ext clock threshold 0V instead of 2.5V
 };
 static inline uint8_t adc_src_4020_bits( unsigned int source )
 {
@@ -1860,6 +1861,7 @@ static int ai_cmd(comedi_device *dev,comedi_subdevice *s)
        comedi_cmd *cmd = &async->cmd;
        u32 bits;
        unsigned int i;
+       unsigned long flags;
 
        disable_ai_interrupts( dev );
 
@@ -1984,7 +1986,6 @@ static int ai_cmd(comedi_device *dev,comedi_subdevice *s)
        if((cmd->flags & TRIG_WAKE_EOS) == 0 ||
                board(dev)->layout == LAYOUT_4020)
        {
-               unsigned long flags;
 
                // set dma transfer size
                for( i = 0; i < DMA_RING_COUNT; i++)
@@ -2007,6 +2008,8 @@ static int ai_cmd(comedi_device *dev,comedi_subdevice *s)
                writew( 0, priv(dev)->main_iobase + DAQ_ATRIG_LOW_4020_REG );
        }
 
+       comedi_spin_lock_irqsave( &dev->spinlock, flags );
+
        /* enable pacing, triggering, etc */
        bits = ADC_ENABLE_BIT | ADC_SOFT_GATE_BITS | ADC_GATE_LEVEL_BIT;
        // set start trigger
@@ -2021,6 +2024,10 @@ static int ai_cmd(comedi_device *dev,comedi_subdevice *s)
                bits |= ADC_SAMPLE_COUNTER_EN_BIT;
        writew(bits, priv(dev)->main_iobase + ADC_CONTROL0_REG);
        DEBUG_PRINT("control0 bits 0x%x\n", bits);
+       
+       priv(dev)->ai_cmd_running = 1;
+
+       comedi_spin_unlock_irqrestore( &dev->spinlock, flags );
 
        // start aquisition
        if( cmd->start_src == TRIG_NOW )
@@ -2029,8 +2036,6 @@ static int ai_cmd(comedi_device *dev,comedi_subdevice *s)
                DEBUG_PRINT("soft trig\n");
        }
 
-       priv(dev)->ai_cmd_running = 1;
-
        return 0;
 }
 
@@ -2246,8 +2251,13 @@ static void handle_interrupt(int irq, void *d, struct pt_regs *regs)
        if( status & ADC_DONE_BIT )
        {
                DEBUG_PRINT("adc done interrupt\n");
+               comedi_spin_lock_irqsave( &dev->spinlock, flags );
                if( priv(dev)->ai_cmd_running )
+               {
+                       comedi_spin_unlock_irqrestore( &dev->spinlock, flags );
                        pio_drain_ai_fifo(dev);
+               }else
+                       comedi_spin_unlock_irqrestore( &dev->spinlock, flags );
        }
 
        // if we are have all the data, then quit
@@ -2320,9 +2330,16 @@ void abort_dma(comedi_device *dev, unsigned int channel)
 
 static int ai_cancel(comedi_device *dev, comedi_subdevice *s)
 {
-       if( priv(dev)->ai_cmd_running == 0 ) return 0;
+       unsigned long flags;
 
+       comedi_spin_lock_irqsave( &dev->spinlock, flags );
+       if( priv(dev)->ai_cmd_running == 0 )
+       {
+               comedi_spin_unlock_irqrestore( &dev->spinlock, flags );
+               return 0;
+       } 
        priv(dev)->ai_cmd_running = 0;
+       comedi_spin_unlock_irqrestore( &dev->spinlock, flags );
 
        // disable ai interrupts
        priv(dev)->intr_enable_bits &= ~EN_ADC_INTR_SRC_BIT & ~EN_ADC_DONE_INTR_BIT &