From e40740ae0615c5d55626af27e3c08c3867db7a9a Mon Sep 17 00:00:00 2001
From: Ian Abbott <abbotti@mev.co.uk>
Date: Mon, 9 Jan 2012 18:35:53 +0000
Subject: [PATCH] --- yaml --- r: 289034 b: refs/heads/master c:
 02f69d67684b77f7f04e281a026a790f0e08b3a3 h: refs/heads/master v: v3

---
 [refs]                                        |  2 +-
 .../staging/comedi/drivers/ni_pcidio.c        | 26 ++++++++++++++++---
 2 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/[refs] b/[refs]
index 66aae59d3e3e..c759aa6a729a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e3794b52f56ac20947a2dbdd505e9ad29013c555
+refs/heads/master: 02f69d67684b77f7f04e281a026a790f0e08b3a3
diff --git a/trunk/drivers/staging/comedi/drivers/ni_pcidio.c b/trunk/drivers/staging/comedi/drivers/ni_pcidio.c
index 5145bf129c86..88728bdf2c65 100644
--- a/trunk/drivers/staging/comedi/drivers/ni_pcidio.c
+++ b/trunk/drivers/staging/comedi/drivers/ni_pcidio.c
@@ -483,6 +483,21 @@ void ni_pcidio_event(struct comedi_device *dev, struct comedi_subdevice *s)
 	comedi_event(dev, s);
 }
 
+static int ni_pcidio_poll(struct comedi_device *dev, struct comedi_subdevice *s)
+{
+	unsigned long irq_flags;
+	int count;
+
+	spin_lock_irqsave(&dev->spinlock, irq_flags);
+	spin_lock(&devpriv->mite_channel_lock);
+	if (devpriv->di_mite_chan)
+		mite_sync_input_dma(devpriv->di_mite_chan, s->async);
+	spin_unlock(&devpriv->mite_channel_lock);
+	count = s->async->buf_write_count - s->async->buf_read_count;
+	spin_unlock_irqrestore(&dev->spinlock, irq_flags);
+	return count;
+}
+
 static irqreturn_t nidio_interrupt(int irq, void *d)
 {
 	struct comedi_device *dev = d;
@@ -498,7 +513,6 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 	int status;
 	int work = 0;
 	unsigned int m_status = 0;
-	unsigned long irq_flags;
 
 	/* interrupcions parasites */
 	if (dev->attached == 0) {
@@ -506,6 +520,9 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 		return IRQ_NONE;
 	}
 
+	/* Lock to avoid race with comedi_poll */
+	spin_lock(&dev->spinlock);
+
 	status = readb(devpriv->mite->daq_io_addr +
 		       Interrupt_And_Window_Status);
 	flags = readb(devpriv->mite->daq_io_addr + Group_1_Flags);
@@ -519,7 +536,7 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 	/* printk("buf[4096]=%08x\n",
 	       *(unsigned int *)(async->prealloc_buf+4096)); */
 
-	spin_lock_irqsave(&devpriv->mite_channel_lock, irq_flags);
+	spin_lock(&devpriv->mite_channel_lock);
 	if (devpriv->di_mite_chan)
 		m_status = mite_get_status(devpriv->di_mite_chan);
 #ifdef MITE_DEBUG
@@ -544,7 +561,7 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 			disable_irq(dev->irq);
 		}
 	}
-	spin_unlock_irqrestore(&devpriv->mite_channel_lock, irq_flags);
+	spin_unlock(&devpriv->mite_channel_lock);
 
 	while (status & DataLeft) {
 		work++;
@@ -646,6 +663,8 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 		       Master_DMA_And_Interrupt_Control);
 	}
 #endif
+
+	spin_unlock(&dev->spinlock);
 	return IRQ_HANDLED;
 }
 
@@ -1252,6 +1271,7 @@ static int nidio_attach(struct comedi_device *dev, struct comedi_devconfig *it)
 		s->len_chanlist = 32;	/* XXX */
 		s->buf_change = &ni_pcidio_change;
 		s->async_dma_dir = DMA_BIDIRECTIONAL;
+		s->poll = &ni_pcidio_poll;
 
 		writel(0, devpriv->mite->daq_io_addr + Port_IO(0));
 		writel(0, devpriv->mite->daq_io_addr + Port_Pin_Directions(0));