Commit 0a679336 authored by Pranjal Shrivastava's avatar Pranjal Shrivastava Committed by Will Deacon
Browse files

iommu/arm-smmu: Set rpm auto_suspend once during probe 

The current code calls arm_smmu_rpm_use_autosuspend() during device
attach, which seems unusual as it sets the autosuspend delay and the
'use_autosuspend' flag for the smmu device. These parameters can be
simply set once during the smmu probe and in order to avoid bouncing
rpm states, we can simply mark_last_busy() during a client dev attach
as discussed in [1].

Move the handling of arm_smmu_rpm_use_autosuspend() to the SMMU probe
and modify the arm_smmu_rpm_put() function to mark_last_busy() before
calling __pm_runtime_put_autosuspend(). Additionally,
s/pm_runtime_put_autosuspend/__pm_runtime_put_autosuspend/ to help with
the refactor of the pm_runtime_put_autosuspend() API [2].

Link: https://lore.kernel.org/r/20241023164835.GF29251@willie-the-truck [1]
Link: https://git.kernel.org/linus/b7d46644e554

 [2]
Signed-off-by: default avatarPranjal Shrivastava <praan@google.com>
Link: https://lore.kernel.org/r/20250123195636.4182099-1-praan@google.com


Signed-off-by: default avatarWill Deacon <will@kernel.org>
parent 0ad2507d

drivers/iommu/arm/arm-smmu/arm-smmu.c

+6 −4
Original line number Diff line number Diff line
@@ -79,8 +79,11 @@ static inline int arm_smmu_rpm_get(struct arm_smmu_device *smmu) 


static inline void arm_smmu_rpm_put(struct arm_smmu_device *smmu)

{

	if (pm_runtime_enabled(smmu->dev))

		pm_runtime_put_autosuspend(smmu->dev);

	if (pm_runtime_enabled(smmu->dev)) {

		pm_runtime_mark_last_busy(smmu->dev);

		__pm_runtime_put_autosuspend(smmu->dev);



	}

}



static void arm_smmu_rpm_use_autosuspend(struct arm_smmu_device *smmu)
@@ -1195,7 +1198,6 @@ static int arm_smmu_attach_dev(struct iommu_domain *domain, struct device *dev) 
	/* Looks ok, so add the device to the domain */

	arm_smmu_master_install_s2crs(cfg, S2CR_TYPE_TRANS,

				      smmu_domain->cfg.cbndx, fwspec);

	arm_smmu_rpm_use_autosuspend(smmu);

rpm_put:

	arm_smmu_rpm_put(smmu);

	return ret;
@@ -1218,7 +1220,6 @@ static int arm_smmu_attach_dev_type(struct device *dev, 
		return ret;



	arm_smmu_master_install_s2crs(cfg, type, 0, fwspec);

	arm_smmu_rpm_use_autosuspend(smmu);

	arm_smmu_rpm_put(smmu);

	return 0;

}
@@ -2246,6 +2247,7 @@ static int arm_smmu_device_probe(struct platform_device *pdev) 
	if (dev->pm_domain) {

		pm_runtime_set_active(dev);

		pm_runtime_enable(dev);

		arm_smmu_rpm_use_autosuspend(smmu);

	}



	return 0;