Messages in this thread | | | Subject | Re: [PATCH v6 4/6] iommu/arm-smmu: Add the device_link between masters and smmu | From | Robin Murphy <> | Date | Wed, 31 Jan 2018 13:09:40 +0000 |
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On 19/01/18 11:43, Vivek Gautam wrote: > From: Sricharan R <sricharan@codeaurora.org> > > 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.
Don't we need to balance this with a device_link_del() in .remove_device (like exynos-iommu does)?
Robin.
> Signed-off-by: Sricharan R <sricharan@codeaurora.org> > --- > drivers/iommu/arm-smmu.c | 11 +++++++++++ > 1 file changed, 11 insertions(+) > > diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c > index 95478bfb182c..33bbcfedb896 100644 > --- a/drivers/iommu/arm-smmu.c > +++ b/drivers/iommu/arm-smmu.c > @@ -1367,6 +1367,7 @@ static int arm_smmu_add_device(struct device *dev) > struct arm_smmu_device *smmu; > struct arm_smmu_master_cfg *cfg; > struct iommu_fwspec *fwspec = dev->iommu_fwspec; > + struct device_link *link; > int i, ret; > > if (using_legacy_binding) { > @@ -1428,6 +1429,16 @@ static int arm_smmu_add_device(struct device *dev) > > pm_runtime_put_sync(smmu->dev); > > + /* > + * 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) > + dev_warn(smmu->dev, "Unable to create device link between %s and %s\n", > + dev_name(smmu->dev), dev_name(dev)); > + > return 0; > > out_cfg_free: >
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