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authorPeter Ujfalusi <peter.ujfalusi@gmail.com>2021-07-17 22:00:21 +0300
committerVinod Koul <vkoul@kernel.org>2021-07-28 10:24:50 +0300
commiteda97cb095f2958bbad55684a6ca3e7d7af0176a (patch)
tree07fc1139c303fe587cd544473474238ee591a503
parentbaa16371c9525f24d508508e4d296c031e1de29c (diff)
downloadlinux-eda97cb095f2958bbad55684a6ca3e7d7af0176a.tar.xz
dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available
If the router_xlate can not find the controller in the available DMA devices then it should return with -EPORBE_DEFER in a same way as the of_dma_request_slave_channel() does. The issue can be reproduced if the event router is registered before the DMA controller itself and a driver would request for a channel before the controller is registered. In of_dma_request_slave_channel(): 1. of_dma_find_controller() would find the dma_router 2. ofdma->of_dma_xlate() would fail and returned NULL 3. -ENODEV is returned as error code with this patch we would return in this case the correct -EPROBE_DEFER and the client can try to request the channel later. Signed-off-by: Peter Ujfalusi <peter.ujfalusi@gmail.com> Link: https://lore.kernel.org/r/20210717190021.21897-1-peter.ujfalusi@gmail.com Signed-off-by: Vinod Koul <vkoul@kernel.org>
-rw-r--r--drivers/dma/of-dma.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c
index ec00b20ae8e4..ac61ecda2926 100644
--- a/drivers/dma/of-dma.c
+++ b/drivers/dma/of-dma.c
@@ -67,8 +67,12 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
return NULL;
ofdma_target = of_dma_find_controller(&dma_spec_target);
- if (!ofdma_target)
- return NULL;
+ if (!ofdma_target) {
+ ofdma->dma_router->route_free(ofdma->dma_router->dev,
+ route_data);
+ chan = ERR_PTR(-EPROBE_DEFER);
+ goto err;
+ }
chan = ofdma_target->of_dma_xlate(&dma_spec_target, ofdma_target);
if (IS_ERR_OR_NULL(chan)) {
@@ -89,6 +93,7 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec,
}
}
+err:
/*
* Need to put the node back since the ofdma->of_dma_route_allocate
* has taken it for generating the new, translated dma_spec