diff options
Diffstat (limited to 'drivers/dma/dmaengine.c')
| -rw-r--r-- | drivers/dma/dmaengine.c | 37 |
1 files changed, 26 insertions, 11 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c index a815d44c70a..b2728d6ba2f 100644 --- a/drivers/dma/dmaengine.c +++ b/drivers/dma/dmaengine.c @@ -62,6 +62,7 @@ #include <linux/rculist.h> #include <linux/idr.h> #include <linux/slab.h> +#include <linux/of_dma.h> static DEFINE_MUTEX(dma_list_mutex); static DEFINE_IDR(dma_idr); @@ -266,7 +267,10 @@ enum dma_status dma_sync_wait(struct dma_chan *chan, dma_cookie_t cookie) pr_err("%s: timeout!\n", __func__); return DMA_ERROR; } - } while (status == DMA_IN_PROGRESS); + if (status != DMA_IN_PROGRESS) + break; + cpu_relax(); + } while (1); return status; } @@ -546,6 +550,21 @@ struct dma_chan *__dma_request_channel(dma_cap_mask_t *mask, dma_filter_fn fn, v } EXPORT_SYMBOL_GPL(__dma_request_channel); +/** + * dma_request_slave_channel - try to allocate an exclusive slave channel + * @dev: pointer to client device structure + * @name: slave channel name + */ +struct dma_chan *dma_request_slave_channel(struct device *dev, char *name) +{ + /* If device-tree is present get slave info from here */ + if (dev->of_node) + return of_dma_request_slave_channel(dev->of_node, name); + + return NULL; +} +EXPORT_SYMBOL_GPL(dma_request_slave_channel); + void dma_release_channel(struct dma_chan *chan) { mutex_lock(&dma_list_mutex); @@ -667,18 +686,14 @@ static int get_dma_id(struct dma_device *device) { int rc; - idr_retry: - if (!idr_pre_get(&dma_idr, GFP_KERNEL)) - return -ENOMEM; mutex_lock(&dma_list_mutex); - rc = idr_get_new(&dma_idr, NULL, &device->dev_id); - mutex_unlock(&dma_list_mutex); - if (rc == -EAGAIN) - goto idr_retry; - else if (rc != 0) - return rc; - return 0; + rc = idr_alloc(&dma_idr, NULL, 0, 0, GFP_KERNEL); + if (rc >= 0) + device->dev_id = rc; + + mutex_unlock(&dma_list_mutex); + return rc < 0 ? rc : 0; } /** |