[PATCH V4 1/4] iommu: of: Fix check for returning EPROBE_DEFER

Sricharan R
2017-05-18T14:55:56Z

Now with IOMMU probe deferral, we return -EPROBE_DEFER
for masters that are connected to an IOMMU which is not
probed yet, but going to get probed, so that we can attach
the correct dma_ops. So while trying to defer the probe of
the master, check if the of_iommu node that it is connected
to is marked in DT as 'status=disabled', then the IOMMU is never
is going to get probed. So simply return NULL and let the master
work without an IOMMU.

Fixes: 7b07cbefb68d ("iommu: of: Handle IOMMU lookup failure with deferred probing or error")
Signed-off-by: Sricharan R <sricharan@codeaurora.org>
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Tested-by: Magnus Damn <magnus.damn@gmail.com>
Acked-by: Will Deacon <will.deacon@arm.com>
---
drivers/iommu/of_iommu.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/drivers/iommu/of_iommu.c b/drivers/iommu/of_iommu.c
index 9f44ee8..e6e9bec 100644
--- a/drivers/iommu/of_iommu.c
+++ b/drivers/iommu/of_iommu.c
@@ -118,6 +118,7 @@ static bool of_iommu_driver_present(struct device_node *np)

ops = iommu_ops_from_fwnode(fwnode);
if ((ops && !ops->of_xlate) ||
+ !of_device_is_available(iommu_spec->np) ||
(!ops && !of_iommu_driver_present(iommu_spec->np)))
return NULL;

--
QUALCOMM INDIA, on behalf of Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation