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| author | Peter Ujfalusi <peter.ujfalusi@gmail.com> | 2021-07-17 22:00:21 +0300 |
|---|---|---|
| committer | Sasha Levin <sashal@kernel.org> | 2021-08-26 08:36:13 -0400 |
| commit | e37cf26bd56d80f1296db73572af630f1717a538 (patch) | |
| tree | d3f001fd0b4029f3b79d311815613b27a31d9bdc /drivers/dma | |
| parent | 12d1322d93a6346483f5dbdd4095d0b64fb1313e (diff) | |
| download | linux-e37cf26bd56d80f1296db73572af630f1717a538.tar.gz linux-e37cf26bd56d80f1296db73572af630f1717a538.tar.bz2 linux-e37cf26bd56d80f1296db73572af630f1717a538.zip | |
dmaengine: of-dma: router_xlate to return -EPROBE_DEFER if controller is not yet available
[ Upstream commit eda97cb095f2958bbad55684a6ca3e7d7af0176a ]
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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'drivers/dma')
| -rw-r--r-- | drivers/dma/of-dma.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/dma/of-dma.c b/drivers/dma/of-dma.c index 4bbf4172b9bf..e3f1d4ab8e4f 100644 --- a/drivers/dma/of-dma.c +++ b/drivers/dma/of-dma.c @@ -65,8 +65,12 @@ 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)) { @@ -77,6 +81,7 @@ static struct dma_chan *of_dma_router_xlate(struct of_phandle_args *dma_spec, chan->route_data = route_data; } +err: /* * Need to put the node back since the ofdma->of_dma_route_allocate * has taken it for generating the new, translated dma_spec |