From e3794b52f56ac20947a2dbdd505e9ad29013c555 Mon Sep 17 00:00:00 2001 From: Ian Abbott Date: Mon, 9 Jan 2012 15:47:31 +0000 Subject: [PATCH] staging: comedi: ni_pcidio: Grab MITE spinlock while preparing 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 Signed-off-by: Greg Kroah-Hartman --- drivers/staging/comedi/drivers/ni_pcidio.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/drivers/staging/comedi/drivers/ni_pcidio.c b/drivers/staging/comedi/drivers/ni_pcidio.c index c9e5f2b2dfbb..5145bf129c86 100644 --- a/drivers/staging/comedi/drivers/ni_pcidio.c +++ b/drivers/staging/comedi/drivers/ni_pcidio.c @@ -436,6 +436,7 @@ static int ni_pcidio_request_di_mite_channel(struct comedi_device *dev) comedi_error(dev, "failed to reserve mite dma channel."); return -EBUSY; } + devpriv->di_mite_chan->dir = COMEDI_INPUT; writeb(primary_DMAChannel_bits(devpriv->di_mite_chan->channel) | secondary_DMAChannel_bits(devpriv->di_mite_chan->channel), devpriv->mite->daq_io_addr + DMA_Line_Control_Group1); @@ -1005,20 +1006,24 @@ static int ni_pcidio_cmd(struct comedi_device *dev, struct comedi_subdevice *s) static int setup_mite_dma(struct comedi_device *dev, struct comedi_subdevice *s) { int retval; + unsigned long flags; retval = ni_pcidio_request_di_mite_channel(dev); if (retval) return retval; - devpriv->di_mite_chan->dir = COMEDI_INPUT; - /* write alloc the entire buffer */ comedi_buf_write_alloc(s->async, s->async->prealloc_bufsz); - mite_prep_dma(devpriv->di_mite_chan, 32, 32); + 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); + } else + retval = -EIO; + spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags); - mite_dma_arm(devpriv->di_mite_chan); - return 0; + return retval; } static int ni_pcidio_inttrig(struct comedi_device *dev, -- 2.20.1