staging: comedi: mite: check for transfer errors in mite_ack_linkc()

Currently only some of the users of mite dma check for transfer errors.

The ni_mio_common code does the check for the analog input and analog
output subdevices. The m-series digital I/O subdevice and the counter
subdevices (handled by ni_tiocmd) do not check.

The ni_pcidio driver checks for the digital input subdevice.

The ni_660x driver counter subdevices (handled by ni_tiocmd) also do
not check.

Move the transfer error checking into mite_ack_linkc() so that the
drivers that use mite don't have to deal with it. This also makes
sure that all the subdevices that use mite for dma will cancel the
async command if a transfer error is detected.

Simplfy the transfer error check by just checking the CHSR_XFERR bit.
This bit will be set if one or more transfer processes terminated with
an error. The actual error is determined by the LERR, MERR, and DERR
bits.
Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Reviewed-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/comedi/drivers/mite.c

@@ -778,7 +778,8 @@ static unsigned int mite_get_status(struct mite_channel *mite_chan)
 	return status;
 }
 
-unsigned int mite_ack_linkc(struct mite_channel *mite_chan)
+unsigned int mite_ack_linkc(struct mite_channel *mite_chan,
+			    struct comedi_subdevice *s)
 {
 	struct mite_struct *mite = mite_chan->mite;
 	unsigned int status;
@@ -787,6 +788,11 @@ unsigned int mite_ack_linkc(struct mite_channel *mite_chan)
 	if (status & CHSR_LINKC)
 		writel(CHOR_CLRLC,
 		       mite->mite_io_addr + MITE_CHOR(mite_chan->channel));
+	if (status & CHSR_XFERR) {
+		dev_err(s->device->class_dev,
+			"mite: transfer error %08x\n", status);
+		s->async->events |= COMEDI_CB_ERROR;
+	}
 
 	return status;
 }

drivers/staging/comedi/drivers/mite.h

@@ -93,7 +93,8 @@ void mite_dma_arm(struct mite_channel *mite_chan);
 void mite_dma_disarm(struct mite_channel *mite_chan);
 void mite_sync_dma(struct mite_channel *mite_chan, struct comedi_subdevice *s);
 u32 mite_bytes_in_transit(struct mite_channel *mite_chan);
-unsigned int mite_ack_linkc(struct mite_channel *mite_chan);
+unsigned int mite_ack_linkc(struct mite_channel *mite_chan,
+			    struct comedi_subdevice *s);
 int mite_done(struct mite_channel *mite_chan);
 
 void mite_prep_dma(struct mite_channel *mite_chan,

drivers/staging/comedi/drivers/ni_mio_common.c

@@ -1317,16 +1317,6 @@ static void handle_a_interrupt(struct comedi_device *dev, unsigned short status,
 #ifdef PCIDMA
 	if (ai_mite_status & CHSR_LINKC)
 		ni_sync_ai_dma(dev);
-
-	if (ai_mite_status & ~(CHSR_INT | CHSR_LINKC | CHSR_DONE | CHSR_MRDY |
-			       CHSR_DRDY | CHSR_DRQ1 | CHSR_DRQ0 | CHSR_ERROR |
-			       CHSR_SABORT | CHSR_XFERR | CHSR_LERR_MASK)) {
-		dev_err(dev->class_dev,
-			"unknown mite interrupt (ai_mite_status=%08x)\n",
-			ai_mite_status);
-		s->async->events |= COMEDI_CB_ERROR;
-		/* disable_irq(dev->irq); */
-	}
 #endif
 
 	/* test for all uncommon interrupt events at the same time */
@@ -1422,15 +1412,6 @@ static void handle_b_interrupt(struct comedi_device *dev,
 
 		mite_handle_b_linkc(devpriv->mite, dev);
 	}
-
-	if (ao_mite_status & ~(CHSR_INT | CHSR_LINKC | CHSR_DONE | CHSR_MRDY |
-			       CHSR_DRDY | CHSR_DRQ1 | CHSR_DRQ0 | CHSR_ERROR |
-			       CHSR_SABORT | CHSR_XFERR | CHSR_LERR_MASK)) {
-		dev_err(dev->class_dev,
-			"unknown mite interrupt (ao_mite_status=%08x)\n",
-			ao_mite_status);
-		s->async->events |= COMEDI_CB_ERROR;
-	}
 #endif
 
 	if (b_status == 0xffff)
@@ -3697,7 +3678,7 @@ static void handle_cdio_interrupt(struct comedi_device *dev)
 
 	spin_lock_irqsave(&devpriv->mite_channel_lock, flags);
 	if (devpriv->cdo_mite_chan) {
-		mite_ack_linkc(devpriv->cdo_mite_chan);
+		mite_ack_linkc(devpriv->cdo_mite_chan, s);
 		mite_sync_dma(devpriv->cdo_mite_chan, s);
 	}
 	spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags);
@@ -5217,9 +5198,11 @@ static irqreturn_t ni_E_interrupt(int irq, void *d)
 
 		spin_lock_irqsave(&devpriv->mite_channel_lock, flags_too);
 		if (devpriv->ai_mite_chan)
-			ai_mite_status = mite_ack_linkc(devpriv->ai_mite_chan);
+			ai_mite_status = mite_ack_linkc(devpriv->ai_mite_chan,
+							dev->read_subdev);
 		if (devpriv->ao_mite_chan)
-			ao_mite_status = mite_ack_linkc(devpriv->ao_mite_chan);
+			ao_mite_status = mite_ack_linkc(devpriv->ao_mite_chan,
+							dev->write_subdev);
 		spin_unlock_irqrestore(&devpriv->mite_channel_lock, flags_too);
 	}
 #endif

drivers/staging/comedi/drivers/ni_pcidio.c

@@ -400,19 +400,13 @@ static irqreturn_t nidio_interrupt(int irq, void *d)
 
 	spin_lock(&devpriv->mite_channel_lock);
 	if (devpriv->di_mite_chan) {
-		unsigned int m_status = mite_ack_linkc(devpriv->di_mite_chan);
+		unsigned int m_status = mite_ack_linkc(devpriv->di_mite_chan,
+						       s);
 
 		if (m_status & CHSR_LINKC) {
 			mite_sync_dma(devpriv->di_mite_chan, s);
 			/* XXX need to byteswap */
 		}
-		if (m_status & ~(CHSR_INT | CHSR_LINKC | CHSR_DONE | CHSR_DRDY |
-				 CHSR_DRQ1 | CHSR_MRDY)) {
-			dev_dbg(dev->class_dev,
-				"unknown mite interrupt, disabling IRQ\n");
-			async->events |= COMEDI_CB_ERROR;
-			disable_irq(dev->irq);
-		}
 	}
 	spin_unlock(&devpriv->mite_channel_lock);
 

drivers/staging/comedi/drivers/ni_tiocmd.c

@@ -429,7 +429,7 @@ void ni_tio_handle_interrupt(struct ni_gpct *counter,
 	}
 	spin_lock_irqsave(&counter->lock, flags);
 	if (counter->mite_chan) {
-		mite_ack_linkc(counter->mite_chan);
+		mite_ack_linkc(counter->mite_chan, s);
 		mite_sync_dma(counter->mite_chan, s);
 	}
 	spin_unlock_irqrestore(&counter->lock, flags);