Hi Sricharan
On 2016-10-22 07:50, Sricharan wrote:
This patch adds runtime pm implementation, which is based on previous
suspend/resume code. SYSMMU controller is now being enabled/disabled mainly
> from the runtime pm callbacks. System sleep callbacks relies on generic
pm_runtime_force_suspend/pm_runtime_force_resume helpers. To ensure
internal state consistency, additional lock for runtime pm transitions
was introduced.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
---
drivers/iommu/exynos-iommu.c | 45 +++++++++++++++++++++++++++++++++++---------
1 file changed, 36 insertions(+), 9 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c
index a959443e6f33..5e6d7bbf9b70 100644
--- a/drivers/iommu/exynos-iommu.c
+++ b/drivers/iommu/exynos-iommu.c
@@ -206,6 +206,7 @@ struct sysmmu_fault_info {
struct exynos_iommu_owner {
struct list_head controllers; /* list of sysmmu_drvdata.owner_node */
struct iommu_domain *domain; /* domain this device is attached */
+ struct mutex rpm_lock; /* for runtime pm of all sysmmus */
};
/*
@@ -594,40 +595,46 @@ static int __init exynos_sysmmu_probe(struct platform_device *pdev)
return 0;
}
-#ifdef CONFIG_PM_SLEEP
-static int exynos_sysmmu_suspend(struct device *dev)
+static int __maybe_unused exynos_sysmmu_suspend(struct device *dev)
{
struct sysmmu_drvdata *data = dev_get_drvdata(dev);
struct device *master = data->master;
if (master) {
- pm_runtime_put(dev);
+ struct exynos_iommu_owner *owner = master->archdata.iommu;
+
+ mutex_lock(&owner->rpm_lock);
More of a device link question,
To understand, i see that with device link + runtime, the supplier
callbacks are not called for irqsafe clients, even if supplier is irqsafe.
Why so ?
Frankly I didn't care about irqsafe runtime pm, because there is no such
need
for Exynos platform and its drivers. Exynos power domain driver also doesn't
support irqsafe mode.
if (data->domain) {
dev_dbg(data->sysmmu, "saving state\n");
__sysmmu_disable(data);
}
+ mutex_unlock(&owner->rpm_lock);
}
return 0;
}
-static int exynos_sysmmu_resume(struct device *dev)
+static int __maybe_unused exynos_sysmmu_resume(struct device *dev)
{
struct sysmmu_drvdata *data = dev_get_drvdata(dev);
struct device *master = data->master;
if (master) {
- pm_runtime_get_sync(dev);
+ struct exynos_iommu_owner *owner = master->archdata.iommu;
+
+ mutex_lock(&owner->rpm_lock);
if (data->domain) {
dev_dbg(data->sysmmu, "restoring state\n");
__sysmmu_enable(data);
}
+ mutex_unlock(&owner->rpm_lock);
}
return 0;
}
-#endif
static const struct dev_pm_ops sysmmu_pm_ops = {
- SET_LATE_SYSTEM_SLEEP_PM_OPS(exynos_sysmmu_suspend, exynos_sysmmu_resume)
+ SET_RUNTIME_PM_OPS(exynos_sysmmu_suspend, exynos_sysmmu_resume, NULL)
+ SET_LATE_SYSTEM_SLEEP_PM_OPS(pm_runtime_force_suspend,
+ pm_runtime_force_resume)
};
Is this needed to be LATE_SYSTEM_SLEEP_PM_OPS with device links to take care
of the order ?
Hmmm. LASE_SYSTEM_SLEEP_PM_OPS is a left over from the previous versions
of the driver,
which doesn't use device links. You are right, that "normal"
SYSTEM_SLEEP_PM_OPS should
be enough assuming that device links will take care of the proper call
sequence between
consumer and supplier device.
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
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