openwrtv4/target/linux/brcm2708/patches-4.4/0088-bcm2835-dma-Fix-up-convert-to-DMA-pool.patch

From 073ad36caa6710db3a90cf2d1214c418cfa47644 Mon Sep 17 00:00:00 2001
From: Matthias Reichl <hias@horus.com>
Date: Mon, 16 Nov 2015 14:05:35 +0000
Subject: [PATCH] bcm2835-dma: Fix up convert to DMA pool

---
 drivers/dma/bcm2835-dma.c | 36 ++++++++++++++++++++++++++----------
 1 file changed, 26 insertions(+), 10 deletions(-)

--- a/drivers/dma/bcm2835-dma.c
+++ b/drivers/dma/bcm2835-dma.c
@@ -488,6 +488,17 @@ static struct dma_async_tx_descriptor *b
 	c->cyclic = true;
 
 	return vchan_tx_prep(&c->vc, &d->vd, flags);
+error_cb:
+	i--;
+	for (; i >= 0; i--) {
+		struct bcm2835_cb_entry *cb_entry = &d->cb_list[i];
+
+		dma_pool_free(c->cb_pool, cb_entry->cb, cb_entry->paddr);
+	}
+
+	kfree(d->cb_list);
+	kfree(d);
+	return NULL;
 }
 
 static struct dma_async_tx_descriptor *
@@ -534,6 +545,7 @@ bcm2835_dma_prep_slave_sg(struct dma_cha
 	if (!d)
 		return NULL;
 
+	d->c = c;
 	d->dir = direction;
 
 	if (c->ch >= 8) /* LITE channel */
@@ -553,15 +565,21 @@ bcm2835_dma_prep_slave_sg(struct dma_cha
 		d->frames += len / max_size + 1;
 	}
 
-	/* Allocate memory for control blocks */
-	d->control_block_size = d->frames * sizeof(struct bcm2835_dma_cb);
-	d->control_block_base = dma_zalloc_coherent(chan->device->dev,
-			d->control_block_size, &d->control_block_base_phys,
-			GFP_NOWAIT);
-	if (!d->control_block_base) {
+	d->cb_list = kcalloc(d->frames, sizeof(*d->cb_list), GFP_KERNEL);
+	if (!d->cb_list) {
 		kfree(d);
 		return NULL;
 	}
+	/* Allocate memory for control blocks */
+	for (i = 0; i < d->frames; i++) {
+		struct bcm2835_cb_entry *cb_entry = &d->cb_list[i];
+
+		cb_entry->cb = dma_pool_zalloc(c->cb_pool, GFP_ATOMIC,
+						&cb_entry->paddr);
+
+		if (!cb_entry->cb)
+			goto error_cb;
+	}
 
 	/*
 	 * Iterate over all SG entries, create a control block
@@ -578,7 +596,7 @@ bcm2835_dma_prep_slave_sg(struct dma_cha
 
 		for (j = 0; j < len; j += max_size) {
 			struct bcm2835_dma_cb *control_block =
-				&d->control_block_base[i + split_cnt];
+				d->cb_list[i + split_cnt].cb;
 
 			/* Setup addresses */
 			if (d->dir == DMA_DEV_TO_MEM) {
@@ -620,9 +638,7 @@ bcm2835_dma_prep_slave_sg(struct dma_cha
 			if (i < sg_len - 1 || len - j > max_size) {
 				/* Next block is the next frame. */
 				control_block->next =
-					d->control_block_base_phys +
-					sizeof(struct bcm2835_dma_cb) *
-					(i + split_cnt + 1);
+					d->cb_list[i + split_cnt + 1].paddr;
 			} else {
 				/* Next block is empty. */
 				control_block->next = 0;