diff mbox

dmaengine: dma_request_chan_by_mask() to handle deferred probing

Message ID 20180718092957.1934-1-peter.ujfalusi@ti.com (mailing list archive)
State Accepted
Headers show

Commit Message

Peter Ujfalusi July 18, 2018, 9:29 a.m. UTC
If there are no DMA devices registered yet, return with EPROBE_DEFER
similarly to the case when requesting a slave channel.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
---
 drivers/dma/dmaengine.c | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

Comments

Vinod Koul July 25, 2018, 12:34 p.m. UTC | #1
On 18-07-18, 12:29, Peter Ujfalusi wrote:
> If there are no DMA devices registered yet, return with EPROBE_DEFER
> similarly to the case when requesting a slave channel.

Applied, thanks
diff mbox

Patch

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index d8fc7b58e506..f62e59e1a264 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -768,8 +768,14 @@  struct dma_chan *dma_request_chan_by_mask(const dma_cap_mask_t *mask)
 		return ERR_PTR(-ENODEV);
 
 	chan = __dma_request_channel(mask, NULL, NULL);
-	if (!chan)
-		chan = ERR_PTR(-ENODEV);
+	if (!chan) {
+		mutex_lock(&dma_list_mutex);
+		if (list_empty(&dma_device_list))
+			chan = ERR_PTR(-EPROBE_DEFER);
+		else
+			chan = ERR_PTR(-ENODEV);
+		mutex_unlock(&dma_list_mutex);
+	}
 
 	return chan;
 }