On 13/03/18 08:55, Vivek Gautam wrote:
From: Sricharan R <sricharan@xxxxxxxxxxxxxx>
Finally add the device link between the master device and
smmu, so that the smmu gets runtime enabled/disabled only when the
master needs it. This is done from add_device callback which gets
called once when the master is added to the smmu.
Signed-off-by: Sricharan R <sricharan@xxxxxxxxxxxxxx>
Signed-off-by: Vivek Gautam <vivek.gautam@xxxxxxxxxxxxxx>
Reviewed-by: Tomasz Figa <tfiga@xxxxxxxxxxxx>
---
drivers/iommu/arm-smmu.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index 56a04ae80bf3..64953ff2281f 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1460,10 +1460,31 @@ static int arm_smmu_add_device(struct device *dev)
iommu_device_link(&smmu->iommu, dev);
+ if (pm_runtime_enabled(smmu->dev)) {
+ struct device_link *link;
+
+ /*
+ * Establish the link between smmu and master, so that the
+ * smmu gets runtime enabled/disabled as per the master's
+ * needs.
+ */
+ link = device_link_add(dev, smmu->dev, DL_FLAG_PM_RUNTIME);
+ if (!link) {
FWIW, given that we don't really care about link itself, I'd be quite
happy to simplify that lot down to:
if (pm_runtime_enabled(smmu_dev) &&
!device_link_add(dev, smmu->dev, DL_FLAG_PM_RUNTIME)) {
+ dev_warn(smmu->dev,
+ "Unable to add link to the consumer %s\n",
+ dev_name(dev));
(side note: since device_link_add() already prints a message on success,
maybe it could print its own failure message too?)
Robin.
+ ret = -ENODEV;
+ goto out_unlink;
+ }
+ }
+
arm_smmu_rpm_put(smmu);
return 0;
+out_unlink:
+ iommu_device_unlink(&smmu->iommu, dev);
+ arm_smmu_master_free_smes(fwspec);
out_rpm_put:
arm_smmu_rpm_put(smmu);
out_cfg_free:
@@ -1486,6 +1507,14 @@ static void arm_smmu_remove_device(struct device *dev)
cfg = fwspec->iommu_priv;
smmu = cfg->smmu;
+ if (pm_runtime_enabled(smmu->dev)) {
+ struct device_link *link;
+
+ link = device_link_find(dev, smmu->dev);
+ if (link)
+ device_link_del(link);
+ }
+
ret = arm_smmu_rpm_get(smmu);
if (ret < 0)
return;
--
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