1 files changed, 31 insertions, 24 deletions

diff --git a/mm/dmapool.c b/mm/dmapool.c
index c5ab33bca0a8..c69781e97cf9 100644
--- a/mm/dmapool.c
+++ b/mm/dmapool.c
@@ -50,7 +50,6 @@ struct dma_pool {		/* the pool */
 	size_t allocation;
 	size_t boundary;
 	char name[32];
-	wait_queue_head_t waitq;
 	struct list_head pools;
 };
 
@@ -62,8 +61,6 @@ struct dma_page {		/* cacheable header for 'allocation' bytes */
 	unsigned int offset;
 };
 
-#define	POOL_TIMEOUT_JIFFIES	((100 /* msec */ * HZ) / 1000)
-
 static DEFINE_MUTEX(pools_lock);
 
 static ssize_t
@@ -172,7 +169,6 @@ struct dma_pool *dma_pool_create(const char *name, struct device *dev,
 	retval->size = size;
 	retval->boundary = boundary;
 	retval->allocation = allocation;
-	init_waitqueue_head(&retval->waitq);
 
 	if (dev) {
 		int ret;
@@ -227,7 +223,6 @@ static struct dma_page *pool_alloc_page(struct dma_pool *pool, gfp_t mem_flags)
 		memset(page->vaddr, POOL_POISON_FREED, pool->allocation);
 #endif
 		pool_initialise_page(pool, page);
-		list_add(&page->page_list, &pool->page_list);
 		page->in_use = 0;
 		page->offset = 0;
 	} else {
@@ -315,30 +310,21 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
 	might_sleep_if(mem_flags & __GFP_WAIT);
 
 	spin_lock_irqsave(&pool->lock, flags);
- restart:
 	list_for_each_entry(page, &pool->page_list, page_list) {
 		if (page->offset < pool->allocation)
 			goto ready;
 	}
-	page = pool_alloc_page(pool, GFP_ATOMIC);
-	if (!page) {
-		if (mem_flags & __GFP_WAIT) {
-			DECLARE_WAITQUEUE(wait, current);
 
-			__set_current_state(TASK_UNINTERRUPTIBLE);
-			__add_wait_queue(&pool->waitq, &wait);
-			spin_unlock_irqrestore(&pool->lock, flags);
+	/* pool_alloc_page() might sleep, so temporarily drop &pool->lock */
+	spin_unlock_irqrestore(&pool->lock, flags);
 
-			schedule_timeout(POOL_TIMEOUT_JIFFIES);
+	page = pool_alloc_page(pool, mem_flags);
+	if (!page)
+		return NULL;
 
-			spin_lock_irqsave(&pool->lock, flags);
-			__remove_wait_queue(&pool->waitq, &wait);
-			goto restart;
-		}
-		retval = NULL;
-		goto done;
-	}
+	spin_lock_irqsave(&pool->lock, flags);
 
+	list_add(&page->page_list, &pool->page_list);
  ready:
 	page->in_use++;
 	offset = page->offset;
@@ -346,9 +332,32 @@ void *dma_pool_alloc(struct dma_pool *pool, gfp_t mem_flags,
 	retval = offset + page->vaddr;
 	*handle = offset + page->dma;
 #ifdef	DMAPOOL_DEBUG
+	{
+		int i;
+		u8 *data = retval;
+		/* page->offset is stored in first 4 bytes */
+		for (i = sizeof(page->offset); i < pool->size; i++) {
+			if (data[i] == POOL_POISON_FREED)
+				continue;
+			if (pool->dev)
+				dev_err(pool->dev,
+					"dma_pool_alloc %s, %p (corruped)\n",
+					pool->name, retval);
+			else
+				pr_err("dma_pool_alloc %s, %p (corruped)\n",
+					pool->name, retval);
+
+			/*
+			 * Dump the first 4 bytes even if they are not
+			 * POOL_POISON_FREED
+			 */
+			print_hex_dump(KERN_ERR, "", DUMP_PREFIX_OFFSET, 16, 1,
+					data, pool->size, 1);
+			break;
+		}
+	}
 	memset(retval, POOL_POISON_ALLOCATED, pool->size);
 #endif
- done:
 	spin_unlock_irqrestore(&pool->lock, flags);
 	return retval;
 }
@@ -435,8 +444,6 @@ void dma_pool_free(struct dma_pool *pool, void *vaddr, dma_addr_t dma)
 	page->in_use--;
 	*(int *)vaddr = page->offset;
 	page->offset = offset;
-	if (waitqueue_active(&pool->waitq))
-		wake_up_locked(&pool->waitq);
 	/*
 	 * Resist a temptation to do
 	 *    if (!is_page_busy(page)) pool_free_page(pool, page);