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-rw-r--r--drivers/dma/dmaengine.c28
-rw-r--r--drivers/dma/mmp_pdma.c30
-rw-r--r--include/linux/dmaengine.h1
3 files changed, 36 insertions, 23 deletions
diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index ea806bdc12ef..4f08ee8c17b4 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -535,6 +535,34 @@ struct dma_chan *dma_get_slave_channel(struct dma_chan *chan)
}
EXPORT_SYMBOL_GPL(dma_get_slave_channel);
+struct dma_chan *dma_get_any_slave_channel(struct dma_device *device)
+{
+ dma_cap_mask_t mask;
+ struct dma_chan *chan;
+ int err;
+
+ dma_cap_zero(mask);
+ dma_cap_set(DMA_SLAVE, mask);
+
+ /* lock against __dma_request_channel */
+ mutex_lock(&dma_list_mutex);
+
+ chan = private_candidate(&mask, device, NULL, NULL);
+ if (chan) {
+ err = dma_chan_get(chan);
+ if (err) {
+ pr_debug("%s: failed to get %s: (%d)\n",
+ __func__, dma_chan_name(chan), err);
+ chan = NULL;
+ }
+ }
+
+ mutex_unlock(&dma_list_mutex);
+
+ return chan;
+}
+EXPORT_SYMBOL_GPL(dma_get_any_slave_channel);
+
/**
* __dma_request_channel - try to allocate an exclusive channel
* @mask: capabilities that the channel must satisfy
diff --git a/drivers/dma/mmp_pdma.c b/drivers/dma/mmp_pdma.c
index dcb1e05149a7..2998f1bffac1 100644
--- a/drivers/dma/mmp_pdma.c
+++ b/drivers/dma/mmp_pdma.c
@@ -893,33 +893,17 @@ static struct dma_chan *mmp_pdma_dma_xlate(struct of_phandle_args *dma_spec,
struct of_dma *ofdma)
{
struct mmp_pdma_device *d = ofdma->of_dma_data;
- struct dma_chan *chan, *candidate;
+ struct dma_chan *chan;
+ struct mmp_pdma_chan *c;
-retry:
- candidate = NULL;
-
- /* walk the list of channels registered with the current instance and
- * find one that is currently unused */
- list_for_each_entry(chan, &d->device.channels, device_node)
- if (chan->client_count == 0) {
- candidate = chan;
- break;
- }
-
- if (!candidate)
+ chan = dma_get_any_slave_channel(&d->device);
+ if (!chan)
return NULL;
- /* dma_get_slave_channel will return NULL if we lost a race between
- * the lookup and the reservation */
- chan = dma_get_slave_channel(candidate);
-
- if (chan) {
- struct mmp_pdma_chan *c = to_mmp_pdma_chan(chan);
- c->drcmr = dma_spec->args[0];
- return chan;
- }
+ c = to_mmp_pdma_chan(chan);
+ c->drcmr = dma_spec->args[0];
- goto retry;
+ return chan;
}
static int mmp_pdma_probe(struct platform_device *op)
diff --git a/include/linux/dmaengine.h b/include/linux/dmaengine.h
index 41cf0c399288..09ef23ee8bce 100644
--- a/include/linux/dmaengine.h
+++ b/include/linux/dmaengine.h
@@ -1079,6 +1079,7 @@ int dma_async_device_register(struct dma_device *device);
void dma_async_device_unregister(struct dma_device *device);
void dma_run_dependencies(struct dma_async_tx_descriptor *tx);
struct dma_chan *dma_get_slave_channel(struct dma_chan *chan);
+struct dma_chan *dma_get_any_slave_channel(struct dma_device *device);
struct dma_chan *net_dma_find_channel(void);
#define dma_request_channel(mask, x, y) __dma_request_channel(&(mask), x, y)
#define dma_request_slave_channel_compat(mask, x, y, dev, name) \
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