fsldma: clean up the OF subsystem routines

This fixes some errors in the cleanup paths of the OF subsystem, including
missing checks for ioremap failing. Also, some variables were renamed for
brevity.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

2 files changed, 134 insertions, 129 deletions

diff --git a/drivers/dma/fsldma.c b/drivers/dma/fsldma.c
index c2db7541c22..507b29716bb 100644
--- a/drivers/dma/fsldma.c
+++ b/drivers/dma/fsldma.c
@@ -40,7 +40,7 @@
 static void dma_init(struct fsldma_chan *fsl_chan)
 {
 	/* Reset the channel */
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, 0, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, 0, 32);
 
 	switch (fsl_chan->feature & FSL_DMA_IP_MASK) {
 	case FSL_DMA_IP_85XX:
@@ -49,7 +49,7 @@ static void dma_init(struct fsldma_chan *fsl_chan)
 		 * EOSIE - End of segments interrupt enable (basic mode)
 		 * EOLNIE - End of links interrupt enable
 		 */
-		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EIE
+		DMA_OUT(fsl_chan, &fsl_chan->regs->mr, FSL_DMA_MR_EIE
 				| FSL_DMA_MR_EOLNIE | FSL_DMA_MR_EOSIE, 32);
 		break;
 	case FSL_DMA_IP_83XX:
@@ -57,7 +57,7 @@ static void dma_init(struct fsldma_chan *fsl_chan)
 		 * EOTIE - End-of-transfer interrupt enable
 		 * PRC_RM - PCI read multiple
 		 */
-		DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, FSL_DMA_MR_EOTIE
+		DMA_OUT(fsl_chan, &fsl_chan->regs->mr, FSL_DMA_MR_EOTIE
 				| FSL_DMA_MR_PRC_RM, 32);
 		break;
 	}
@@ -66,12 +66,12 @@ static void dma_init(struct fsldma_chan *fsl_chan)
 
 static void set_sr(struct fsldma_chan *fsl_chan, u32 val)
 {
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->sr, val, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->sr, val, 32);
 }
 
 static u32 get_sr(struct fsldma_chan *fsl_chan)
 {
-	return DMA_IN(fsl_chan, &fsl_chan->reg_base->sr, 32);
+	return DMA_IN(fsl_chan, &fsl_chan->regs->sr, 32);
 }
 
 static void set_desc_cnt(struct fsldma_chan *fsl_chan,
@@ -112,27 +112,27 @@ static void set_desc_next(struct fsldma_chan *fsl_chan,
 
 static void set_cdar(struct fsldma_chan *fsl_chan, dma_addr_t addr)
 {
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->cdar, addr | FSL_DMA_SNEN, 64);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->cdar, addr | FSL_DMA_SNEN, 64);
 }
 
 static dma_addr_t get_cdar(struct fsldma_chan *fsl_chan)
 {
-	return DMA_IN(fsl_chan, &fsl_chan->reg_base->cdar, 64) & ~FSL_DMA_SNEN;
+	return DMA_IN(fsl_chan, &fsl_chan->regs->cdar, 64) & ~FSL_DMA_SNEN;
 }
 
 static void set_ndar(struct fsldma_chan *fsl_chan, dma_addr_t addr)
 {
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->ndar, addr, 64);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->ndar, addr, 64);
 }
 
 static dma_addr_t get_ndar(struct fsldma_chan *fsl_chan)
 {
-	return DMA_IN(fsl_chan, &fsl_chan->reg_base->ndar, 64);
+	return DMA_IN(fsl_chan, &fsl_chan->regs->ndar, 64);
 }
 
 static u32 get_bcr(struct fsldma_chan *fsl_chan)
 {
-	return DMA_IN(fsl_chan, &fsl_chan->reg_base->bcr, 32);
+	return DMA_IN(fsl_chan, &fsl_chan->regs->bcr, 32);
 }
 
 static int dma_is_idle(struct fsldma_chan *fsl_chan)
@@ -145,11 +145,11 @@ static void dma_start(struct fsldma_chan *fsl_chan)
 {
 	u32 mode;
 
-	mode = DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32);
+	mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
 
 	if ((fsl_chan->feature & FSL_DMA_IP_MASK) == FSL_DMA_IP_85XX) {
 		if (fsl_chan->feature & FSL_DMA_CHAN_PAUSE_EXT) {
-			DMA_OUT(fsl_chan, &fsl_chan->reg_base->bcr, 0, 32);
+			DMA_OUT(fsl_chan, &fsl_chan->regs->bcr, 0, 32);
 			mode |= FSL_DMA_MR_EMP_EN;
 		} else {
 			mode &= ~FSL_DMA_MR_EMP_EN;
@@ -161,7 +161,7 @@ static void dma_start(struct fsldma_chan *fsl_chan)
 	else
 		mode |= FSL_DMA_MR_CS;
 
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 }
 
 static void dma_halt(struct fsldma_chan *fsl_chan)
@@ -169,12 +169,12 @@ static void dma_halt(struct fsldma_chan *fsl_chan)
 	u32 mode;
 	int i;
 
-	mode = DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32);
+	mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
 	mode |= FSL_DMA_MR_CA;
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 
 	mode &= ~(FSL_DMA_MR_CS | FSL_DMA_MR_EMS_EN | FSL_DMA_MR_CA);
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 
 	for (i = 0; i < 100; i++) {
 		if (dma_is_idle(fsl_chan))
@@ -235,7 +235,7 @@ static void fsl_chan_set_src_loop_size(struct fsldma_chan *fsl_chan, int size)
 {
 	u32 mode;
 
-	mode = DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32);
+	mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
 
 	switch (size) {
 	case 0:
@@ -249,7 +249,7 @@ static void fsl_chan_set_src_loop_size(struct fsldma_chan *fsl_chan, int size)
 		break;
 	}
 
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 }
 
 /**
@@ -267,7 +267,7 @@ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *fsl_chan, int size)
 {
 	u32 mode;
 
-	mode = DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32);
+	mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
 
 	switch (size) {
 	case 0:
@@ -281,7 +281,7 @@ static void fsl_chan_set_dst_loop_size(struct fsldma_chan *fsl_chan, int size)
 		break;
 	}
 
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 }
 
 /**
@@ -302,10 +302,10 @@ static void fsl_chan_set_request_count(struct fsldma_chan *fsl_chan, int size)
 
 	BUG_ON(size > 1024);
 
-	mode = DMA_IN(fsl_chan, &fsl_chan->reg_base->mr, 32);
+	mode = DMA_IN(fsl_chan, &fsl_chan->regs->mr, 32);
 	mode |= (__ilog2(size) << 24) & 0x0f000000;
 
-	DMA_OUT(fsl_chan, &fsl_chan->reg_base->mr, mode, 32);
+	DMA_OUT(fsl_chan, &fsl_chan->regs->mr, mode, 32);
 }
 
 /**
@@ -967,7 +967,7 @@ static enum dma_status fsl_dma_is_complete(struct dma_chan *chan,
 	return dma_async_is_complete(cookie, last_complete, last_used);
 }
 
-static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data)
+static irqreturn_t fsldma_chan_irq(int irq, void *data)
 {
 	struct fsldma_chan *fsl_chan = data;
 	u32 stat;
@@ -1048,17 +1048,17 @@ static irqreturn_t fsl_dma_chan_do_interrupt(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static irqreturn_t fsl_dma_do_interrupt(int irq, void *data)
+static irqreturn_t fsldma_irq(int irq, void *data)
 {
 	struct fsldma_device *fdev = data;
 	int ch_nr;
 	u32 gsr;
 
-	gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->reg_base)
-			: in_le32(fdev->reg_base);
+	gsr = (fdev->feature & FSL_DMA_BIG_ENDIAN) ? in_be32(fdev->regs)
+			: in_le32(fdev->regs);
 	ch_nr = (32 - ffs(gsr)) / 8;
 
-	return fdev->chan[ch_nr] ? fsl_dma_chan_do_interrupt(irq,
+	return fdev->chan[ch_nr] ? fsldma_chan_irq(irq,
 			fdev->chan[ch_nr]) : IRQ_NONE;
 }
 
@@ -1075,140 +1075,142 @@ static void dma_do_tasklet(unsigned long data)
 static int __devinit fsl_dma_chan_probe(struct fsldma_device *fdev,
 	struct device_node *node, u32 feature, const char *compatible)
 {
-	struct fsldma_chan *new_fsl_chan;
+	struct fsldma_chan *fchan;
 	struct resource res;
 	int err;
 
 	/* alloc channel */
-	new_fsl_chan = kzalloc(sizeof(*new_fsl_chan), GFP_KERNEL);
-	if (!new_fsl_chan) {
-		dev_err(fdev->dev, "No free memory for allocating "
-				"dma channels!\n");
-		return -ENOMEM;
+	fchan = kzalloc(sizeof(*fchan), GFP_KERNEL);
+	if (!fchan) {
+		dev_err(fdev->dev, "no free memory for DMA channels!\n");
+		err = -ENOMEM;
+		goto out_return;
+	}
+
+	/* ioremap registers for use */
+	fchan->regs = of_iomap(node, 0);
+	if (!fchan->regs) {
+		dev_err(fdev->dev, "unable to ioremap registers\n");
+		err = -ENOMEM;
+		goto out_free_fchan;
 	}
 
-	/* get dma channel register base */
 	err = of_address_to_resource(node, 0, &res);
 	if (err) {
-		dev_err(fdev->dev, "Can't get %s property 'reg'\n",
-				node->full_name);
-		goto err_no_reg;
+		dev_err(fdev->dev, "unable to find 'reg' property\n");
+		goto out_iounmap_regs;
 	}
 
-	new_fsl_chan->feature = feature;
-
+	fchan->feature = feature;
 	if (!fdev->feature)
-		fdev->feature = new_fsl_chan->feature;
+		fdev->feature = fchan->feature;
 
-	/* If the DMA device's feature is different than its channels',
-	 * report the bug.
+	/*
+	 * If the DMA device's feature is different than the feature
+	 * of its channels, report the bug
 	 */
-	WARN_ON(fdev->feature != new_fsl_chan->feature);
-
-	new_fsl_chan->dev = fdev->dev;
-	new_fsl_chan->reg_base = ioremap(res.start, resource_size(&res));
-	new_fsl_chan->id = ((res.start - 0x100) & 0xfff) >> 7;
-	if (new_fsl_chan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
-		dev_err(fdev->dev, "There is no %d channel!\n",
-				new_fsl_chan->id);
+	WARN_ON(fdev->feature != fchan->feature);
+
+	fchan->dev = fdev->dev;
+	fchan->id = ((res.start - 0x100) & 0xfff) >> 7;
+	if (fchan->id >= FSL_DMA_MAX_CHANS_PER_DEVICE) {
+		dev_err(fdev->dev, "too many channels for device\n");
 		err = -EINVAL;
-		goto err_no_chan;
+		goto out_iounmap_regs;
 	}
-	fdev->chan[new_fsl_chan->id] = new_fsl_chan;
-	tasklet_init(&new_fsl_chan->tasklet, dma_do_tasklet,
-			(unsigned long)new_fsl_chan);
 
-	/* Init the channel */
-	dma_init(new_fsl_chan);
+	fdev->chan[fchan->id] = fchan;
+	tasklet_init(&fchan->tasklet, dma_do_tasklet, (unsigned long)fchan);
+
+	/* Initialize the channel */
+	dma_init(fchan);
 
 	/* Clear cdar registers */
-	set_cdar(new_fsl_chan, 0);
+	set_cdar(fchan, 0);
 
-	switch (new_fsl_chan->feature & FSL_DMA_IP_MASK) {
+	switch (fchan->feature & FSL_DMA_IP_MASK) {
 	case FSL_DMA_IP_85XX:
-		new_fsl_chan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
+		fchan->toggle_ext_pause = fsl_chan_toggle_ext_pause;
 	case FSL_DMA_IP_83XX:
-		new_fsl_chan->toggle_ext_start = fsl_chan_toggle_ext_start;
-		new_fsl_chan->set_src_loop_size = fsl_chan_set_src_loop_size;
-		new_fsl_chan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
-		new_fsl_chan->set_request_count = fsl_chan_set_request_count;
+		fchan->toggle_ext_start = fsl_chan_toggle_ext_start;
+		fchan->set_src_loop_size = fsl_chan_set_src_loop_size;
+		fchan->set_dst_loop_size = fsl_chan_set_dst_loop_size;
+		fchan->set_request_count = fsl_chan_set_request_count;
 	}
 
-	spin_lock_init(&new_fsl_chan->desc_lock);
-	INIT_LIST_HEAD(&new_fsl_chan->ld_queue);
+	spin_lock_init(&fchan->desc_lock);
+	INIT_LIST_HEAD(&fchan->ld_queue);
 
-	new_fsl_chan->common.device = &fdev->common;
+	fchan->common.device = &fdev->common;
 
 	/* Add the channel to DMA device channel list */
-	list_add_tail(&new_fsl_chan->common.device_node,
-			&fdev->common.channels);
+	list_add_tail(&fchan->common.device_node, &fdev->common.channels);
 	fdev->common.chancnt++;
 
-	new_fsl_chan->irq = irq_of_parse_and_map(node, 0);
-	if (new_fsl_chan->irq != NO_IRQ) {
-		err = request_irq(new_fsl_chan->irq,
-					&fsl_dma_chan_do_interrupt, IRQF_SHARED,
-					"fsldma-channel", new_fsl_chan);
+	fchan->irq = irq_of_parse_and_map(node, 0);
+	if (fchan->irq != NO_IRQ) {
+		err = request_irq(fchan->irq, &fsldma_chan_irq,
+				  IRQF_SHARED, "fsldma-channel", fchan);
 		if (err) {
-			dev_err(fdev->dev, "DMA channel %s request_irq error "
-				"with return %d\n", node->full_name, err);
-			goto err_no_irq;
+			dev_err(fdev->dev, "unable to request IRQ "
+					   "for channel %d\n", fchan->id);
+			goto out_list_del;
 		}
 	}
 
-	dev_info(fdev->dev, "#%d (%s), irq %d\n", new_fsl_chan->id,
-		 compatible,
-		 new_fsl_chan->irq != NO_IRQ ? new_fsl_chan->irq : fdev->irq);
+	dev_info(fdev->dev, "#%d (%s), irq %d\n", fchan->id, compatible,
+		 fchan->irq != NO_IRQ ? fchan->irq : fdev->irq);
 
 	return 0;
 
-err_no_irq:
-	list_del(&new_fsl_chan->common.device_node);
-err_no_chan:
-	iounmap(new_fsl_chan->reg_base);
-err_no_reg:
-	kfree(new_fsl_chan);
+out_list_del:
+	irq_dispose_mapping(fchan->irq);
+	list_del_init(&fchan->common.device_node);
+out_iounmap_regs:
+	iounmap(fchan->regs);
+out_free_fchan:
+	kfree(fchan);
+out_return:
 	return err;
 }
 
 static void fsl_dma_chan_remove(struct fsldma_chan *fchan)
 {
-	if (fchan->irq != NO_IRQ)
+	if (fchan->irq != NO_IRQ) {
 		free_irq(fchan->irq, fchan);
+		irq_dispose_mapping(fchan->irq);
+	}
+
 	list_del(&fchan->common.device_node);
-	iounmap(fchan->reg_base);
+	iounmap(fchan->regs);
 	kfree(fchan);
 }
 
-static int __devinit fsldma_of_probe(struct of_device *dev,
+static int __devinit fsldma_of_probe(struct of_device *op,
 			const struct of_device_id *match)
 {
-	int err;
 	struct fsldma_device *fdev;
 	struct device_node *child;
-	struct resource res;
+	int err;
 
 	fdev = kzalloc(sizeof(*fdev), GFP_KERNEL);
 	if (!fdev) {
-		dev_err(&dev->dev, "No enough memory for 'priv'\n");
-		return -ENOMEM;
+		dev_err(&op->dev, "No enough memory for 'priv'\n");
+		err = -ENOMEM;
+		goto out_return;
 	}
-	fdev->dev = &dev->dev;
+
+	fdev->dev = &op->dev;
 	INIT_LIST_HEAD(&fdev->common.channels);
 
-	/* get DMA controller register base */
-	err = of_address_to_resource(dev->node, 0, &res);
-	if (err) {
-		dev_err(&dev->dev, "Can't get %s property 'reg'\n",
-				dev->node->full_name);
-		goto err_no_reg;
+	/* ioremap the registers for use */
+	fdev->regs = of_iomap(op->node, 0);
+	if (!fdev->regs) {
+		dev_err(&op->dev, "unable to ioremap registers\n");
+		err = -ENOMEM;
+		goto out_free_fdev;
 	}
 
-	dev_info(&dev->dev, "Probe the Freescale DMA driver for %s "
-			"controller at 0x%llx...\n",
-			match->compatible, (unsigned long long)res.start);
-	fdev->reg_base = ioremap(res.start, resource_size(&res));
-
 	dma_cap_set(DMA_MEMCPY, fdev->common.cap_mask);
 	dma_cap_set(DMA_INTERRUPT, fdev->common.cap_mask);
 	dma_cap_set(DMA_SLAVE, fdev->common.cap_mask);
@@ -1220,66 +1222,69 @@ static int __devinit fsldma_of_probe(struct of_device *dev,
 	fdev->common.device_issue_pending = fsl_dma_memcpy_issue_pending;
 	fdev->common.device_prep_slave_sg = fsl_dma_prep_slave_sg;
 	fdev->common.device_terminate_all = fsl_dma_device_terminate_all;
-	fdev->common.dev = &dev->dev;
+	fdev->common.dev = &op->dev;
 
-	fdev->irq = irq_of_parse_and_map(dev->node, 0);
+	fdev->irq = irq_of_parse_and_map(op->node, 0);
 	if (fdev->irq != NO_IRQ) {
-		err = request_irq(fdev->irq, &fsl_dma_do_interrupt, IRQF_SHARED,
-					"fsldma-device", fdev);
+		err = request_irq(fdev->irq, &fsldma_irq, IRQF_SHARED,
+				  "fsldma-device", fdev);
 		if (err) {
-			dev_err(&dev->dev, "DMA device request_irq error "
-				"with return %d\n", err);
-			goto err;
+			dev_err(&op->dev, "unable to request IRQ\n");
+			goto out_iounmap_regs;
 		}
 	}
 
-	dev_set_drvdata(&(dev->dev), fdev);
+	dev_set_drvdata(&op->dev, fdev);
 
-	/* We cannot use of_platform_bus_probe() because there is no
-	 * of_platform_bus_remove.  Instead, we manually instantiate every DMA
+	/*
+	 * We cannot use of_platform_bus_probe() because there is no
+	 * of_platform_bus_remove(). Instead, we manually instantiate every DMA
 	 * channel object.
 	 */
-	for_each_child_of_node(dev->node, child) {
-		if (of_device_is_compatible(child, "fsl,eloplus-dma-channel"))
+	for_each_child_of_node(op->node, child) {
+		if (of_device_is_compatible(child, "fsl,eloplus-dma-channel")) {
 			fsl_dma_chan_probe(fdev, child,
 				FSL_DMA_IP_85XX | FSL_DMA_BIG_ENDIAN,
 				"fsl,eloplus-dma-channel");
-		if (of_device_is_compatible(child, "fsl,elo-dma-channel"))
+		}
+
+		if (of_device_is_compatible(child, "fsl,elo-dma-channel")) {
 			fsl_dma_chan_probe(fdev, child,
 				FSL_DMA_IP_83XX | FSL_DMA_LITTLE_ENDIAN,
 				"fsl,elo-dma-channel");
+		}
 	}
 
 	dma_async_device_register(&fdev->common);
 	return 0;
 
-err:
-	iounmap(fdev->reg_base);
-err_no_reg:
+out_iounmap_regs:
+	iounmap(fdev->regs);
+out_free_fdev:
 	kfree(fdev);
+out_return:
 	return err;
 }
 
-static int fsldma_of_remove(struct of_device *of_dev)
+static int fsldma_of_remove(struct of_device *op)
 {
 	struct fsldma_device *fdev;
 	unsigned int i;
 
-	fdev = dev_get_drvdata(&of_dev->dev);
-
+	fdev = dev_get_drvdata(&op->dev);
 	dma_async_device_unregister(&fdev->common);
 
-	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++)
+	for (i = 0; i < FSL_DMA_MAX_CHANS_PER_DEVICE; i++) {
 		if (fdev->chan[i])
 			fsl_dma_chan_remove(fdev->chan[i]);
+	}
 
 	if (fdev->irq != NO_IRQ)
 		free_irq(fdev->irq, fdev);
 
-	iounmap(fdev->reg_base);
-
+	iounmap(fdev->regs);
+	dev_set_drvdata(&op->dev, NULL);
 	kfree(fdev);
-	dev_set_drvdata(&of_dev->dev, NULL);
 
 	return 0;
 }
diff --git a/drivers/dma/fsldma.h b/drivers/dma/fsldma.h
index a67b8e3df0f..ea3b19c8708 100644
--- a/drivers/dma/fsldma.h
+++ b/drivers/dma/fsldma.h
@@ -108,7 +108,7 @@ struct fsldma_chan;
 #define FSL_DMA_MAX_CHANS_PER_DEVICE 4
 
 struct fsldma_device {
-	void __iomem *reg_base;	/* DGSR register base */
+	void __iomem *regs;	/* DGSR register base */
 	struct device *dev;
 	struct dma_device common;
 	struct fsldma_chan *chan[FSL_DMA_MAX_CHANS_PER_DEVICE];
@@ -128,7 +128,7 @@ struct fsldma_device {
 #define FSL_DMA_CHAN_START_EXT	0x00002000
 
 struct fsldma_chan {
-	struct fsldma_chan_regs __iomem *reg_base;
+	struct fsldma_chan_regs __iomem *regs;
 	dma_cookie_t completed_cookie;	/* The maximum cookie completed */
 	spinlock_t desc_lock;		/* Descriptor operation lock */
 	struct list_head ld_queue;	/* Link descriptors queue */