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[V4,4/6] iommu/arm-smmu: Add the device_link between masters and smmu

Message ID 1499333825-7658-5-git-send-email-vivek.gautam@codeaurora.org (mailing list archive)
State Not Applicable
Delegated to: Stephen Boyd
Headers show

Commit Message

Vivek Gautam July 6, 2017, 9:37 a.m. UTC 
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.

Signed-off-by: Sricharan R <sricharan@codeaurora.org>
---
 drivers/iommu/arm-smmu.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Stephen Boyd July 12, 2017, 10:55 p.m. UTC | #1 
On 07/06, Vivek Gautam wrote:
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index ddbfa8ab69e6..75567d9698ab 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -1348,6 +1348,7 @@ 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 = NULL;

Unnecessary initialization?

>  	int i, ret;
>  
>  	if (using_legacy_binding) {
> @@ -1403,6 +1404,16 @@ 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;
>
Vivek Gautam July 13, 2017, 3:59 a.m. UTC | #2 
On 07/13/2017 04:25 AM, Stephen Boyd wrote:
> On 07/06, Vivek Gautam wrote:
>> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
>> index ddbfa8ab69e6..75567d9698ab 100644
>> --- a/drivers/iommu/arm-smmu.c
>> +++ b/drivers/iommu/arm-smmu.c
>> @@ -1348,6 +1348,7 @@ 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 = NULL;
> Unnecessary initialization?

Right, will drop this.
Thanks.

>
>>   	int i, ret;
>>   
>>   	if (using_legacy_binding) {
>> @@ -1403,6 +1404,16 @@ 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;
>>
diff mbox

Patch

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index ddbfa8ab69e6..75567d9698ab 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -1348,6 +1348,7 @@  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 = NULL;
 	int i, ret;
 
 	if (using_legacy_binding) {
@@ -1403,6 +1404,16 @@  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: