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dmaengine: Add matching device node validation in __dma_request_channel()

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When user try to request one DMA channel by __dma_request_channel(), it won't
validate if it is the correct DMA device to request, that will lead each DMA
engine driver to validate the correct device node in their filter function
if it is necessary.

Thus we can add the matching device node validation in the DMA engine core,
to remove all of device node validation in the drivers.

Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Baolin Wang
2019-05-20 19:32:14 +08:00
committed by Vinod Koul
parent f935d7dc81
commit f5151311c3
3 changed files with 18 additions and 8 deletions
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10
drivers/dma/dmaengine.c
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@@ -641,11 +641,13 @@ EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
* @mask: capabilities that the channel must satisfy
* @fn: optional callback to disposition available channels
* @fn_param: opaque parameter to pass to dma_filter_fn
* @np: device node to look for DMA channels
*
* Returns pointer to appropriate DMA channel on success or NULL.
*/
struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
dma_filter_fn fn, void *fn_param)
dma_filter_fn fn, void *fn_param,
struct device_node *np)
{
struct dma_device *device, *_d;
struct dma_chan *chan = NULL;
@@ -653,6 +655,10 @@ struct dma_chan *__dma_request_channel(const dma_cap_mask_t *mask,
/* Find a channel */
mutex_lock(&dma_list_mutex);
list_for_each_entry_safe(device, _d, &dma_device_list, global_node) {
/* Finds a DMA controller with matching device node */
if (np && device->dev->of_node && np != device->dev->of_node)
continue;
chan = find_candidate(device, mask, fn, fn_param);
if (!IS_ERR(chan))
break;
@@ -769,7 +775,7 @@ struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
if (!mask)
return ERR_PTR(-ENODEV);
chan = __dma_request_channel(mask, NULL, NULL);
chan = __dma_request_channel(mask, NULL, NULL, NULL);
if (!chan) {
mutex_lock(&dma_list_mutex);
if (list_empty(&dma_device_list))