[PATCH] iommu/arm-smmu-qcom: record reason for deferring probe

[Zhenhua Huang]

To avoid deferring probe smmu driver silently, record reason for it.
It can be checked through ../debugfs/devices_deferred as well:
/sys/kernel/debug# cat devices_deferred
15000000.iommu  arm-smmu: qcom_scm not ready

Signed-off-by: Zhenhua Huang <quic_zhenhuah at quicinc.com>
---
 drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
index 25f034677f56..971c6a2e592b 100644
--- a/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
+++ b/drivers/iommu/arm/arm-smmu/arm-smmu-qcom.c
@@ -469,7 +469,8 @@ static struct arm_smmu_device *qcom_smmu_create(struct arm_smmu_device *smmu,
 
 	/* Check to make sure qcom_scm has finished probing */
 	if (!qcom_scm_is_available())
-		return ERR_PTR(-EPROBE_DEFER);
+		return ERR_PTR(dev_err_probe(smmu->dev, -EPROBE_DEFER,
+			"qcom_scm not ready\n"));
 
 	qsmmu = devm_krealloc(smmu->dev, smmu, sizeof(*qsmmu), GFP_KERNEL);
 	if (!qsmmu)
-- 
2.7.4