Merge branch 'coh' into dmaengine

7 files changed, 116 insertions, 123 deletions

diff --git a/arch/arm/mach-u300/include/mach/coh901318.h b/arch/arm/mach-u300/include/mach/coh901318.h
index f4cfee9c7d28..b8155b4e5ffa 100644
--- a/arch/arm/mach-u300/include/mach/coh901318.h
+++ b/arch/arm/mach-u300/include/mach/coh901318.h
@@ -53,7 +53,7 @@ struct coh901318_params {
  * struct coh_dma_channel - dma channel base
  * @name: ascii name of dma channel
  * @number: channel id number
- * @desc_nbr_max: number of preallocated descriptortors
+ * @desc_nbr_max: number of preallocated descriptors
  * @priority_high: prio of channel, 0 low otherwise high.
  * @param: configuration parameters
  * @dev_addr: physical address of periphal connected to channel
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index b5f2ee0f8e2c..1656fdcdb6c2 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -39,7 +39,6 @@ struct coh901318_desc {
 	unsigned int sg_len;
 	struct coh901318_lli *data;
 	enum dma_data_direction dir;
-	int pending_irqs;
 	unsigned long flags;
 };
 
@@ -72,7 +71,6 @@ struct coh901318_chan {
 
 	unsigned long nbr_active_done;
 	unsigned long busy;
-	int pending_irqs;
 
 	struct coh901318_base *base;
 };
@@ -80,18 +78,16 @@ struct coh901318_chan {
 static void coh901318_list_print(struct coh901318_chan *cohc,
 				 struct coh901318_lli *lli)
 {
-	struct coh901318_lli *l;
-	dma_addr_t addr =  virt_to_phys(lli);
+	struct coh901318_lli *l = lli;
 	int i = 0;
 
-	while (addr) {
-		l = phys_to_virt(addr);
+	while (l) {
 		dev_vdbg(COHC_2_DEV(cohc), "i %d, lli %p, ctrl 0x%x, src 0x%x"
-			 ", dst 0x%x, link 0x%x link_virt 0x%p\n",
+			 ", dst 0x%x, link 0x%x virt_link_addr 0x%p\n",
 			 i, l, l->control, l->src_addr, l->dst_addr,
-			 l->link_addr, phys_to_virt(l->link_addr));
+			 l->link_addr, l->virt_link_addr);
 		i++;
-		addr = l->link_addr;
+		l = l->virt_link_addr;
 	}
 }
 
@@ -125,7 +121,7 @@ static int coh901318_debugfs_read(struct file *file, char __user *buf,
 		goto err_kmalloc;
 	tmp = dev_buf;
 
-	tmp += sprintf(tmp, "DMA -- enable dma channels\n");
+	tmp += sprintf(tmp, "DMA -- enabled dma channels\n");
 
 	for (i = 0; i < debugfs_dma_base->platform->max_channels; i++)
 		if (started_channels & (1 << i))
@@ -337,16 +333,22 @@ coh901318_desc_get(struct coh901318_chan *cohc)
 		 * TODO: alloc a pile of descs instead of just one,
 		 * avoid many small allocations.
 		 */
-		desc = kmalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
+		desc = kzalloc(sizeof(struct coh901318_desc), GFP_NOWAIT);
 		if (desc == NULL)
 			goto out;
 		INIT_LIST_HEAD(&desc->node);
+		dma_async_tx_descriptor_init(&desc->desc, &cohc->chan);
 	} else {
 		/* Reuse an old desc. */
 		desc = list_first_entry(&cohc->free,
 					struct coh901318_desc,
 					node);
 		list_del(&desc->node);
+		/* Initialize it a bit so it's not insane */
+		desc->sg = NULL;
+		desc->sg_len = 0;
+		desc->desc.callback = NULL;
+		desc->desc.callback_param = NULL;
 	}
 
  out:
@@ -364,10 +366,6 @@ static void
 coh901318_desc_submit(struct coh901318_chan *cohc, struct coh901318_desc *desc)
 {
 	list_add_tail(&desc->node, &cohc->active);
-
-	BUG_ON(cohc->pending_irqs != 0);
-
-	cohc->pending_irqs = desc->pending_irqs;
 }
 
 static struct coh901318_desc *
@@ -592,6 +590,10 @@ static struct coh901318_desc *coh901318_queue_start(struct coh901318_chan *cohc)
 	return cohd_que;
 }
 
+/*
+ * This tasklet is called from the interrupt handler to
+ * handle each descriptor (DMA job) that is sent to a channel.
+ */
 static void dma_tasklet(unsigned long data)
 {
 	struct coh901318_chan *cohc = (struct coh901318_chan *) data;
@@ -600,57 +602,58 @@ static void dma_tasklet(unsigned long data)
 	dma_async_tx_callback callback;
 	void *callback_param;
 
+	dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d"
+		 " nbr_active_done %ld\n", __func__,
+		 cohc->id, cohc->nbr_active_done);
+
 	spin_lock_irqsave(&cohc->lock, flags);
 
-	/* get first active entry from list */
+	/* get first active descriptor entry from list */
 	cohd_fin = coh901318_first_active_get(cohc);
 
-	BUG_ON(cohd_fin->pending_irqs == 0);
-
 	if (cohd_fin == NULL)
 		goto err;
 
-	cohd_fin->pending_irqs--;
-	cohc->completed = cohd_fin->desc.cookie;
-
-	BUG_ON(cohc->nbr_active_done && cohd_fin == NULL);
-
-	if (cohc->nbr_active_done == 0)
-		return;
+	/* locate callback to client */
+	callback = cohd_fin->desc.callback;
+	callback_param = cohd_fin->desc.callback_param;
 
-	if (!cohd_fin->pending_irqs) {
-		/* release the lli allocation*/
-		coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
-	}
+	/* sign this job as completed on the channel */
+	cohc->completed = cohd_fin->desc.cookie;
 
-	dev_vdbg(COHC_2_DEV(cohc), "[%s] chan_id %d pending_irqs %d"
-		 " nbr_active_done %ld\n", __func__,
-		 cohc->id, cohc->pending_irqs, cohc->nbr_active_done);
+	/* release the lli allocation and remove the descriptor */
+	coh901318_lli_free(&cohc->base->pool, &cohd_fin->data);
 
-	/* callback to client */
-	callback = cohd_fin->desc.callback;
-	callback_param = cohd_fin->desc.callback_param;
+	/* return desc to free-list */
+	coh901318_desc_remove(cohd_fin);
+	coh901318_desc_free(cohc, cohd_fin);
 
-	if (!cohd_fin->pending_irqs) {
-		coh901318_desc_remove(cohd_fin);
+	spin_unlock_irqrestore(&cohc->lock, flags);
 
-		/* return desc to free-list */
-		coh901318_desc_free(cohc, cohd_fin);
-	}
+	/* Call the callback when we're done */
+	if (callback)
+		callback(callback_param);
 
-	if (cohc->nbr_active_done)
-		cohc->nbr_active_done--;
+	spin_lock_irqsave(&cohc->lock, flags);
 
+	/*
+	 * If another interrupt fired while the tasklet was scheduling,
+	 * we don't get called twice, so we have this number of active
+	 * counter that keep track of the number of IRQs expected to
+	 * be handled for this channel. If there happen to be more than
+	 * one IRQ to be ack:ed, we simply schedule this tasklet again.
+	 */
+	cohc->nbr_active_done--;
 	if (cohc->nbr_active_done) {
+		dev_dbg(COHC_2_DEV(cohc), "scheduling tasklet again, new IRQs "
+			"came in while we were scheduling this tasklet\n");
 		if (cohc_chan_conf(cohc)->priority_high)
 			tasklet_hi_schedule(&cohc->tasklet);
 		else
 			tasklet_schedule(&cohc->tasklet);
 	}
-	spin_unlock_irqrestore(&cohc->lock, flags);
 
-	if (callback)
-		callback(callback_param);
+	spin_unlock_irqrestore(&cohc->lock, flags);
 
 	return;
 
@@ -669,16 +672,17 @@ static void dma_tc_handle(struct coh901318_chan *cohc)
 	if (!cohc->allocated)
 		return;
 
-	BUG_ON(cohc->pending_irqs == 0);
+	spin_lock(&cohc->lock);
 
-	cohc->pending_irqs--;
 	cohc->nbr_active_done++;
 
-	if (cohc->pending_irqs == 0 && coh901318_queue_start(cohc) == NULL)
+	if (coh901318_queue_start(cohc) == NULL)
 		cohc->busy = 0;
 
 	BUG_ON(list_empty(&cohc->active));
 
+	spin_unlock(&cohc->lock);
+
 	if (cohc_chan_conf(cohc)->priority_high)
 		tasklet_hi_schedule(&cohc->tasklet);
 	else
@@ -872,6 +876,7 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 	int lli_len;
 	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+	int ret;
 
 	spin_lock_irqsave(&cohc->lock, flg);
 
@@ -892,22 +897,19 @@ coh901318_prep_memcpy(struct dma_chan *chan, dma_addr_t dest, dma_addr_t src,
 	if (data == NULL)
 		goto err;
 
-	cohd = coh901318_desc_get(cohc);
-	cohd->sg = NULL;
-	cohd->sg_len = 0;
-	cohd->data = data;
-
-	cohd->pending_irqs =
-		coh901318_lli_fill_memcpy(
-				&cohc->base->pool, data, src, size, dest,
-				cohc_chan_param(cohc)->ctrl_lli_chained,
-				ctrl_last);
-	cohd->flags = flags;
+	ret = coh901318_lli_fill_memcpy(
+		&cohc->base->pool, data, src, size, dest,
+		cohc_chan_param(cohc)->ctrl_lli_chained,
+		ctrl_last);
+	if (ret)
+		goto err;
 
 	COH_DBG(coh901318_list_print(cohc, data));
 
-	dma_async_tx_descriptor_init(&cohd->desc, chan);
-
+	/* Pick a descriptor to handle this transfer */
+	cohd = coh901318_desc_get(cohc);
+	cohd->data = data;
+	cohd->flags = flags;
 	cohd->desc.tx_submit = coh901318_tx_submit;
 
 	spin_unlock_irqrestore(&cohc->lock, flg);
@@ -926,6 +928,7 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	struct coh901318_chan *cohc = to_coh901318_chan(chan);
 	struct coh901318_lli *data;
 	struct coh901318_desc *cohd;
+	const struct coh901318_params *params;
 	struct scatterlist *sg;
 	int len = 0;
 	int size;
@@ -933,7 +936,9 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 	u32 ctrl_chained = cohc_chan_param(cohc)->ctrl_lli_chained;
 	u32 ctrl = cohc_chan_param(cohc)->ctrl_lli;
 	u32 ctrl_last = cohc_chan_param(cohc)->ctrl_lli_last;
+	u32 config;
 	unsigned long flg;
+	int ret;
 
 	if (!sgl)
 		goto out;
@@ -949,15 +954,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		/* Trigger interrupt after last lli */
 		ctrl_last |= COH901318_CX_CTRL_TC_IRQ_ENABLE;
 
-	cohd = coh901318_desc_get(cohc);
-	cohd->sg = NULL;
-	cohd->sg_len = 0;
-	cohd->dir = direction;
+	params = cohc_chan_param(cohc);
+	config = params->config;
 
 	if (direction == DMA_TO_DEVICE) {
 		u32 tx_flags = COH901318_CX_CTRL_PRDD_SOURCE |
 			COH901318_CX_CTRL_SRC_ADDR_INC_ENABLE;
 
+		config |= COH901318_CX_CFG_RM_MEMORY_TO_PRIMARY;
 		ctrl_chained |= tx_flags;
 		ctrl_last |= tx_flags;
 		ctrl |= tx_flags;
@@ -965,16 +969,14 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		u32 rx_flags = COH901318_CX_CTRL_PRDD_DEST |
 			COH901318_CX_CTRL_DST_ADDR_INC_ENABLE;
 
+		config |= COH901318_CX_CFG_RM_PRIMARY_TO_MEMORY;
 		ctrl_chained |= rx_flags;
 		ctrl_last |= rx_flags;
 		ctrl |= rx_flags;
 	} else
 		goto err_direction;
 
-	dma_async_tx_descriptor_init(&cohd->desc, chan);
-
-	cohd->desc.tx_submit = coh901318_tx_submit;
-
+	coh901318_set_conf(cohc, config);
 
 	/* The dma only supports transmitting packages up to
 	 * MAX_DMA_PACKET_SIZE. Calculate to total number of
@@ -996,32 +998,37 @@ coh901318_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
 		len += factor;
 	}
 
+	pr_debug("Allocate %d lli:s for this transfer\n", len);
 	data = coh901318_lli_alloc(&cohc->base->pool, len);
 
 	if (data == NULL)
 		goto err_dma_alloc;
 
 	/* initiate allocated data list */
-	cohd->pending_irqs =
-		coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
-				      cohc_dev_addr(cohc),
-				      ctrl_chained,
-				      ctrl,
-				      ctrl_last,
-				      direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
-	cohd->data = data;
-
-	cohd->flags = flags;
+	ret = coh901318_lli_fill_sg(&cohc->base->pool, data, sgl, sg_len,
+				    cohc_dev_addr(cohc),
+				    ctrl_chained,
+				    ctrl,
+				    ctrl_last,
+				    direction, COH901318_CX_CTRL_TC_IRQ_ENABLE);
+	if (ret)
+		goto err_lli_fill;
 
 	COH_DBG(coh901318_list_print(cohc, data));
 
+	/* Pick a descriptor to handle this transfer */
+	cohd = coh901318_desc_get(cohc);
+	cohd->dir = direction;
+	cohd->flags = flags;
+	cohd->desc.tx_submit = coh901318_tx_submit;
+	cohd->data = data;
+
 	spin_unlock_irqrestore(&cohc->lock, flg);
 
 	return &cohd->desc;
+ err_lli_fill:
  err_dma_alloc:
  err_direction:
-	coh901318_desc_remove(cohd);
-	coh901318_desc_free(cohc, cohd);
 	spin_unlock_irqrestore(&cohc->lock, flg);
  out:
 	return NULL;
@@ -1094,9 +1101,8 @@ coh901318_terminate_all(struct dma_chan *chan)
 		/* release the lli allocation*/
 		coh901318_lli_free(&cohc->base->pool, &cohd->data);
 
-		coh901318_desc_remove(cohd);
-
 		/* return desc to free-list */
+		coh901318_desc_remove(cohd);
 		coh901318_desc_free(cohc, cohd);
 	}
 
@@ -1104,16 +1110,14 @@ coh901318_terminate_all(struct dma_chan *chan)
 		/* release the lli allocation*/
 		coh901318_lli_free(&cohc->base->pool, &cohd->data);
 
-		coh901318_desc_remove(cohd);
-
 		/* return desc to free-list */
+		coh901318_desc_remove(cohd);
 		coh901318_desc_free(cohc, cohd);
 	}
 
 
 	cohc->nbr_active_done = 0;
 	cohc->busy = 0;
-	cohc->pending_irqs = 0;
 
 	spin_unlock_irqrestore(&cohc->lock, flags);
 }
@@ -1140,7 +1144,6 @@ void coh901318_base_init(struct dma_device *dma, const int *pick_chans,
 
 			spin_lock_init(&cohc->lock);
 
-			cohc->pending_irqs = 0;
 			cohc->nbr_active_done = 0;
 			cohc->busy = 0;
 			INIT_LIST_HEAD(&cohc->free);
@@ -1256,12 +1259,17 @@ static int __init coh901318_probe(struct platform_device *pdev)
 	base->dma_memcpy.device_issue_pending = coh901318_issue_pending;
 	base->dma_memcpy.device_terminate_all = coh901318_terminate_all;
 	base->dma_memcpy.dev = &pdev->dev;
+	/*
+	 * This controller can only access address at even 32bit boundaries,
+	 * i.e. 2^2
+	 */
+	base->dma_memcpy.copy_align = 2;
 	err = dma_async_device_register(&base->dma_memcpy);
 
 	if (err)
 		goto err_register_memcpy;
 
-	dev_dbg(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
+	dev_info(&pdev->dev, "Initialized COH901318 DMA on virtual base 0x%08x\n",
 		(u32) base->virtbase);
 
 	return err;
diff --git a/drivers/dma/coh901318_lli.c b/drivers/dma/coh901318_lli.c
index f5120f238a4d..71d58c1a1e86 100644
--- a/drivers/dma/coh901318_lli.c
+++ b/drivers/dma/coh901318_lli.c
@@ -74,6 +74,8 @@ coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
 
 	lli = head;
 	lli->phy_this = phy;
+	lli->link_addr = 0x00000000;
+	lli->virt_link_addr = 0x00000000U;
 
 	for (i = 1; i < len; i++) {
 		lli_prev = lli;
@@ -85,13 +87,13 @@ coh901318_lli_alloc(struct coh901318_pool *pool, unsigned int len)
 
 		DEBUGFS_POOL_COUNTER_ADD(pool, 1);
 		lli->phy_this = phy;
+		lli->link_addr = 0x00000000;
+		lli->virt_link_addr = 0x00000000U;
 
 		lli_prev->link_addr = phy;
 		lli_prev->virt_link_addr = lli;
 	}
 
-	lli->link_addr = 0x00000000U;
-
 	spin_unlock(&pool->lock);
 
 	return head;
@@ -166,8 +168,7 @@ coh901318_lli_fill_memcpy(struct coh901318_pool *pool,
 	lli->src_addr = src;
 	lli->dst_addr = dst;
 
-	/* One irq per single transfer */
-	return 1;
+	return 0;
 }
 
 int
@@ -223,8 +224,7 @@ coh901318_lli_fill_single(struct coh901318_pool *pool,
 	lli->src_addr = src;
 	lli->dst_addr = dst;
 
-	/* One irq per single transfer */
-	return 1;
+	return 0;
 }
 
 int
@@ -240,7 +240,6 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
 	u32 ctrl_sg;
 	dma_addr_t src = 0;
 	dma_addr_t dst = 0;
-	int nbr_of_irq = 0;
 	u32 bytes_to_transfer;
 	u32 elem_size;
 
@@ -269,15 +268,12 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
 			ctrl_sg = ctrl ? ctrl : ctrl_last;
 
 
-		if ((ctrl_sg & ctrl_irq_mask))
-			nbr_of_irq++;
-
 		if (dir == DMA_TO_DEVICE)
 			/* increment source address */
-			src = sg_dma_address(sg);
+			src = sg_phys(sg);
 		else
 			/* increment destination address */
-			dst =  sg_dma_address(sg);
+			dst =  sg_phys(sg);
 
 		bytes_to_transfer = sg_dma_len(sg);
 
@@ -310,8 +306,7 @@ coh901318_lli_fill_sg(struct coh901318_pool *pool,
 	}
 	spin_unlock(&pool->lock);
 
-	/* There can be many IRQs per sg transfer */
-	return nbr_of_irq;
+	return 0;
  err:
 	spin_unlock(&pool->lock);
 	return -EINVAL;
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 6f51a0a7a8bb..e7a3230fb7d5 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -826,6 +826,7 @@ void dma_async_device_unregister(struct dma_device *device)
 		chan->dev->chan = NULL;
 		mutex_unlock(&dma_list_mutex);
 		device_unregister(&chan->dev->device);
+		free_percpu(chan->local);
 	}
 }
 EXPORT_SYMBOL(dma_async_device_unregister);
diff --git a/drivers/dma/dmatest.c b/drivers/dma/dmatest.c
index 8e409fb50fc0..6fa55fe3dd24 100644
--- a/drivers/dma/dmatest.c
+++ b/drivers/dma/dmatest.c
@@ -467,7 +467,7 @@ err_srcs:
 
 	if (iterations > 0)
 		while (!kthread_should_stop()) {
-			DECLARE_WAIT_QUEUE_HEAD(wait_dmatest_exit);
+			DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wait_dmatest_exit);
 			interruptible_sleep_on(&wait_dmatest_exit);
 		}
 
diff --git a/drivers/dma/ioat/dma_v2.c b/drivers/dma/ioat/dma_v2.c
index 25a3c72b2941..1ed5d66d7dca 100644
--- a/drivers/dma/ioat/dma_v2.c
+++ b/drivers/dma/ioat/dma_v2.c
@@ -241,7 +241,7 @@ int ioat2_quiesce(struct ioat_chan_common *chan, unsigned long tmo)
 	if (is_ioat_active(status) || is_ioat_idle(status))
 		ioat_suspend(chan);
 	while (is_ioat_active(status) || is_ioat_idle(status)) {
-		if (end && time_after(jiffies, end)) {
+		if (tmo && time_after(jiffies, end)) {
 			err = -ETIMEDOUT;
 			break;
 		}
diff --git a/drivers/dma/ipu/ipu_idmac.c b/drivers/dma/ipu/ipu_idmac.c
index 1c518f1cc49b..2a446397c884 100644
--- a/drivers/dma/ipu/ipu_idmac.c
+++ b/drivers/dma/ipu/ipu_idmac.c
@@ -748,12 +748,10 @@ static void ipu_select_buffer(enum ipu_channel channel, int buffer_n)
  * @buffer_n:	buffer number to update.
  *		0 or 1 are the only valid values.
  * @phyaddr:	buffer physical address.
- * @return:	Returns 0 on success or negative error code on failure. This
- *              function will fail if the buffer is set to ready.
  */
 /* Called under spin_lock(_irqsave)(&ichan->lock) */
-static int ipu_update_channel_buffer(struct idmac_channel *ichan,
-				     int buffer_n, dma_addr_t phyaddr)
+static void ipu_update_channel_buffer(struct idmac_channel *ichan,
+				      int buffer_n, dma_addr_t phyaddr)
 {
 	enum ipu_channel channel = ichan->dma_chan.chan_id;
 	uint32_t reg;
@@ -793,8 +791,6 @@ static int ipu_update_channel_buffer(struct idmac_channel *ichan,
 	}
 
 	spin_unlock_irqrestore(&ipu_data.lock, flags);
-
-	return 0;
 }
 
 /* Called under spin_lock_irqsave(&ichan->lock) */
@@ -803,7 +799,6 @@ static int ipu_submit_buffer(struct idmac_channel *ichan,
 {
 	unsigned int chan_id = ichan->dma_chan.chan_id;
 	struct device *dev = &ichan->dma_chan.dev->device;
-	int ret;
 
 	if (async_tx_test_ack(&desc->txd))
 		return -EINTR;
@@ -814,14 +809,7 @@ static int ipu_submit_buffer(struct idmac_channel *ichan,
 	 * could make it conditional on status >= IPU_CHANNEL_ENABLED, but
 	 * doing it again shouldn't hurt either.
 	 */
-	ret = ipu_update_channel_buffer(ichan, buf_idx,
-					sg_dma_address(sg));
-
-	if (ret < 0) {
-		dev_err(dev, "Updating sg %p on channel 0x%x buffer %d failed!\n",
-			sg, chan_id, buf_idx);
-		return ret;
-	}
+	ipu_update_channel_buffer(ichan, buf_idx, sg_dma_address(sg));
 
 	ipu_select_buffer(chan_id, buf_idx);
 	dev_dbg(dev, "Updated sg %p on channel 0x%x buffer %d\n",
@@ -1366,10 +1354,11 @@ static irqreturn_t idmac_interrupt(int irq, void *dev_id)
 
 	if (likely(sgnew) &&
 	    ipu_submit_buffer(ichan, descnew, sgnew, ichan->active_buffer) < 0) {
-		callback = desc->txd.callback;
-		callback_param = desc->txd.callback_param;
+		callback = descnew->txd.callback;
+		callback_param = descnew->txd.callback_param;
 		spin_unlock(&ichan->lock);
-		callback(callback_param);
+		if (callback)
+			callback(callback_param);
 		spin_lock(&ichan->lock);
 	}