FAILED: patch "[PATCH] PM / Domains: defer dev_pm_domain_set() until" failed to apply to 4.4-stable tree

FAILED: patch "[PATCH] PM / Domains: defer dev_pm_domain_set() until" failed to apply to 4.4-stable tree

[gregkh]

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

>From 975e83cfb8dc16e7a2fdc58188c77c0c605876c2 Mon Sep 17 00:00:00 2001
From: Sudeep Holla <Sudeep.Holla@arm.com>
Date: Fri, 14 Jul 2017 11:51:48 +0100
Subject: [PATCH] PM / Domains: defer dev_pm_domain_set() until
 genpd->attach_dev succeeds if present

If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach
may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets
the PM domain for the device unconditionally.

When subsequent attempts are made to call genpd_dev_pm_attach, it may
return -EEXISTS checking dev->pm_domain without re-attempting to call
attach_dev or power_on.

platform_drv_probe then attempts to call drv->probe as the return value
-EEXIST != -EPROBE_DEFER, which may end up in a situation where the
device is accessed without it's power domain switched on.

Fixes: f104e1e5ef57 (PM / Domains: Re-order initialization of generic_pm_domain_data)
Cc: 4.4+ <stable@vger.kernel.org> # v4.4+
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index 2ac906288a6f..91ba82688f4c 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1222,8 +1222,6 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 
 	spin_unlock_irq(&dev->power.lock);
 
-	dev_pm_domain_set(dev, &genpd->domain);
-
 	return gpd_data;
 
  err_free:
@@ -1237,8 +1235,6 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 static void genpd_free_dev_data(struct device *dev,
 				struct generic_pm_domain_data *gpd_data)
 {
-	dev_pm_domain_set(dev, NULL);
-
 	spin_lock_irq(&dev->power.lock);
 
 	dev->power.subsys_data->domain_data = NULL;
@@ -1275,6 +1271,8 @@ static int genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (ret)
 		goto out;
 
+	dev_pm_domain_set(dev, &genpd->domain);
+
 	genpd->device_count++;
 	genpd->max_off_time_changed = true;
 
@@ -1336,6 +1334,8 @@ static int genpd_remove_device(struct generic_pm_domain *genpd,
 	if (genpd->detach_dev)
 		genpd->detach_dev(genpd, dev);
 
+	dev_pm_domain_set(dev, NULL);
+
 	list_del_init(&pdd->list_node);
 
 	genpd_unlock(genpd);

[PATCH v4.4 STABLE] PM / Domains: defer setting dev->pm_domain until genpd->attach_dev succeeds if present

[Sudeep Holla]

commit 975e83cfb8dc16e7a2fdc58188c77c0c605876c2 upstream.

If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach
may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets
the PM domain for the device unconditionally.

When subsequent attempts are made to call genpd_dev_pm_attach, it may
return -EEXISTS checking dev->pm_domain without re-attempting to call
attach_dev or power_on.

platform_drv_probe then attempts to call drv->probe as the return value
-EEXIST != -EPROBE_DEFER, which may end up in a situation where the
device is accessed without it's power domain switched on.

Fixes: f104e1e5ef57 (PM / Domains: Re-order initialization of generic_pm_domain_data)
Cc: 4.4+ <stable@vger.kernel.org> # v4.4+
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 drivers/base/power/domain.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/base/power/domain.c b/drivers/base/power/domain.c
index a48824deabc5..da5718e7fbb7 100644
--- a/drivers/base/power/domain.c
+++ b/drivers/base/power/domain.c
@@ -1188,7 +1188,6 @@ static struct generic_pm_domain_data *genpd_alloc_dev_data(struct device *dev,
 	}

 	dev->power.subsys_data->domain_data = &gpd_data->base;
-	dev->pm_domain = &genpd->domain;

 	spin_unlock_irq(&dev->power.lock);

@@ -1207,7 +1206,6 @@ static void genpd_free_dev_data(struct device *dev,
 {
 	spin_lock_irq(&dev->power.lock);

-	dev->pm_domain = NULL;
 	dev->power.subsys_data->domain_data = NULL;

 	spin_unlock_irq(&dev->power.lock);
@@ -1248,6 +1246,8 @@ int __pm_genpd_add_device(struct generic_pm_domain *genpd, struct device *dev,
 	if (ret)
 		goto out;

+	dev->pm_domain = &genpd->domain;
+
 	genpd->device_count++;
 	genpd->max_off_time_changed = true;

@@ -1299,6 +1299,8 @@ int pm_genpd_remove_device(struct generic_pm_domain *genpd,
 	if (genpd->detach_dev)
 		genpd->detach_dev(genpd, dev);

+	dev->pm_domain = NULL;
+
 	list_del_init(&pdd->list_node);

 	mutex_unlock(&genpd->lock);
--
2.7.4

Re: [PATCH v4.4 STABLE] PM / Domains: defer setting dev->pm_domain until genpd->attach_dev succeeds if present

[Greg KH]

On Wed, Jul 26, 2017 at 11:07:35AM +0100, Sudeep Holla wrote:
> commit 975e83cfb8dc16e7a2fdc58188c77c0c605876c2 upstream.
> 
> If the genpd->attach_dev or genpd->power_on fails, genpd_dev_pm_attach
> may return -EPROBE_DEFER initially. However genpd_alloc_dev_data sets
> the PM domain for the device unconditionally.
> 
> When subsequent attempts are made to call genpd_dev_pm_attach, it may
> return -EEXISTS checking dev->pm_domain without re-attempting to call
> attach_dev or power_on.
> 
> platform_drv_probe then attempts to call drv->probe as the return value
> -EEXIST != -EPROBE_DEFER, which may end up in a situation where the
> device is accessed without it's power domain switched on.
> 
> Fixes: f104e1e5ef57 (PM / Domains: Re-order initialization of generic_pm_domain_data)
> Cc: 4.4+ <stable@vger.kernel.org> # v4.4+
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> Acked-by: Ulf Hansson <ulf.hansson@linaro.org>
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
> ---
>  drivers/base/power/domain.c | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)

Now applied, thanks.

greg k-h