ni_pcidio: Grab MITE channel spinlock while preparing and arming DMA.

When setting up the DMA for 'read' streaming acquisition command, grab
the MITE channel spinlock before preparing and arming the DMA.

Change inspired by ni_ai_setup_MITE_dma() in ni_mio_common.c.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>

diff --git a/comedi/drivers/ni_pcidio.c b/comedi/drivers/ni_pcidio.c
index b39a2cf8ae1b75494e3ebd97ccb6e770aa483c64..1e66cd4393479da2ba4c4238b8b33cd17ba3e75a 100644 (file)
--- a/comedi/drivers/ni_pcidio.c
+++ b/comedi/drivers/ni_pcidio.c
@@ -1000,10 +1000,16 @@ static int setup_mite_dma(comedi_device * dev, comedi_subdevice * s)
        /* write alloc the entire buffer */
        comedi_buf_write_alloc(s->async, s->async->prealloc_bufsz);
 
-       mite_prep_dma(devpriv->di_mite_chan, 32, 32);
+       comedi_spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
+       if (devpriv->di_mite_chan) {
+               mite_prep_dma(devpriv->di_mite_chan, 32, 32);
 
-       mite_dma_arm(devpriv->di_mite_chan);
-       return 0;
+               mite_dma_arm(devpriv->di_mite_chan);
+       } else
+               retval = -EIO;
+       comedi_spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
+
+       return retval;
 }
 
 static int ni_pcidio_inttrig(comedi_device * dev, comedi_subdevice * s,