diff options
| -rw-r--r-- | drivers/staging/comedi/drivers/ni_660x.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/drivers/staging/comedi/drivers/ni_660x.c b/drivers/staging/comedi/drivers/ni_660x.c index 377a78a..43aab61 100644 --- a/drivers/staging/comedi/drivers/ni_660x.c +++ b/drivers/staging/comedi/drivers/ni_660x.c @@ -428,6 +428,8 @@ struct ni_660x_private { struct mite_dma_descriptor_ring *mite_rings[NI_660X_MAX_NUM_CHIPS][counters_per_chip]; spinlock_t mite_channel_lock; + /* interrupt_lock prevents races between interrupt and comedi_poll */ + spinlock_t interrupt_lock; unsigned dma_configuration_soft_copies[NI_660X_MAX_NUM_CHIPS]; spinlock_t soft_reg_copy_lock; unsigned short pfi_output_selects[NUM_PFI_CHANNELS]; @@ -914,17 +916,32 @@ static irqreturn_t ni_660x_interrupt(int irq, void *d) struct comedi_device *dev = d; struct comedi_subdevice *s; unsigned i; + unsigned long flags; if (dev->attached == 0) return IRQ_NONE; + /* lock to avoid race with comedi_poll */ + comedi_spin_lock_irqsave(&private(dev)->interrupt_lock, flags); smp_mb(); for (i = 0; i < ni_660x_num_counters(dev); ++i) { s = dev->subdevices + NI_660X_GPCT_SUBDEV(i); ni_660x_handle_gpct_interrupt(dev, s); } + comedi_spin_unlock_irqrestore(&private(dev)->interrupt_lock, flags); return IRQ_HANDLED; } +static int ni_660x_input_poll(struct comedi_device *dev, + struct comedi_subdevice *s) +{ + unsigned long flags; + /* lock to avoid race with comedi_poll */ + comedi_spin_lock_irqsave(&private(dev)->interrupt_lock, flags); + mite_sync_input_dma(subdev_to_counter(s)->mite_chan, s->async); + comedi_spin_unlock_irqrestore(&private(dev)->interrupt_lock, flags); + return comedi_buf_read_n_available(s->async); +} + static int ni_660x_buf_change(struct comedi_device * dev, struct comedi_subdevice * s, unsigned long new_size) { @@ -946,6 +963,7 @@ static int ni_660x_allocate_private(struct comedi_device * dev) if ((retval = alloc_private(dev, sizeof(struct ni_660x_private))) < 0) return retval; spin_lock_init(&private(dev)->mite_channel_lock); + spin_lock_init(&private(dev)->interrupt_lock); spin_lock_init(&private(dev)->soft_reg_copy_lock); for (i = 0; i < NUM_PFI_CHANNELS; ++i) { private(dev)->pfi_output_selects[i] = pfi_output_select_counter; @@ -1055,6 +1073,7 @@ static int ni_660x_attach(struct comedi_device * dev, struct comedi_devconfig * s->len_chanlist = 1; s->do_cmdtest = &ni_660x_cmdtest; s->cancel = &ni_660x_cancel; + s->poll = &ni_660x_input_poll; s->async_dma_dir = DMA_BIDIRECTIONAL; s->buf_change = &ni_660x_buf_change; s->private = &private(dev)->counter_dev->counters[i]; |