UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

dmaengine: dma_request_chan_by_mask() to handle deferred probing 

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>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
This commit is contained in:
Peter Ujfalusi 2018-07-18 12:29:57 +03:00 committed by Vinod Koul
parent d8095f94e1
commit ec8ca8e3b4
1 changed files with 8 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
drivers/dma/dmaengine.c
View File

@ -770,8 +770,14 @@ 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)
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;
}