linux-kernel - [PATCH v2 1/2] driver core: detach device's pm_domain after devres_release

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Message-Id: <1502786217-212887-2-git-send-email-shawn.lin@rock-chips.com>
Date:   Tue, 15 Aug 2017 16:36:56 +0800
From:   Shawn Lin <shawn.lin@...k-chips.com>
To:     Ulf Hansson <ulf.hansson@...aro.org>,
        "Rafael J. Wysocki" <rjw@...ysocki.net>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>
Cc:     Heiko Stuebner <heiko@...ech.de>,
        Jaehoon Chung <jh80.chung@...sung.com>,
        linux-mmc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Shawn Lin <shawn.lin@...k-chips.com>
Subject: [PATCH v2 1/2] driver core: detach device's pm_domain after devres_release_all

Move dev_pm_domain_detach after devres_release_all to avoid
accessing device's registers with genpd been powered off.

Signed-off-by: Shawn Lin <shawn.lin@...k-chips.com>
---

Changes in v2: None

 drivers/base/dd.c       | 35 ++++++++++++++++++++++++++++++-----
 drivers/base/platform.c | 18 ++----------------
 2 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/drivers/base/dd.c b/drivers/base/dd.c
index ad44b40..13dc0ad 100644
--- a/drivers/base/dd.c
+++ b/drivers/base/dd.c
@@ -25,7 +25,9 @@
 #include <linux/kthread.h>
 #include <linux/wait.h>
 #include <linux/async.h>
+#include <linux/platform_device.h>
 #include <linux/pm_runtime.h>
+#include <linux/pm_domain.h>
 #include <linux/pinctrl/devinfo.h>
 
 #include "base.h"
@@ -356,6 +358,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 	int local_trigger_count = atomic_read(&deferred_trigger_count);
 	bool test_remove = IS_ENABLED(CONFIG_DEBUG_TEST_DRIVER_REMOVE) &&
 			   !drv->suppress_bind_attrs;
+	struct platform_driver *pdrv;
+	bool do_pm_domain = false;
 
 	if (defer_all_probes) {
 		/*
@@ -414,6 +418,16 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 		if (ret)
 			goto probe_failed;
 	} else if (drv->probe) {
+		ret = dev_pm_domain_attach(dev, true);
+		pdrv = to_platform_driver(dev->driver);
+		/* don't fail if just dev_pm_domain_attach failed */
+		if (pdrv->prevent_deferred_probe &&
+		    ret == -EPROBE_DEFER) {
+			dev_warn(dev, "probe deferral not supported\n");
+			ret = -ENXIO;
+			goto probe_failed;
+		}
+		do_pm_domain = true;
 		ret = drv->probe(dev);
 		if (ret)
 			goto probe_failed;
@@ -421,13 +435,17 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 
 	if (test_remove) {
 		test_remove = false;
+		do_pm_domain = false;
 
-		if (dev->bus->remove)
+		if (dev->bus->remove) {
 			dev->bus->remove(dev);
-		else if (drv->remove)
+		} else if (drv->remove) {
 			drv->remove(dev);
-
+			do_pm_domain = true;
+		}
 		devres_release_all(dev);
+		if (do_pm_domain)
+			dev_pm_domain_detach(dev, true);
 		driver_sysfs_remove(dev);
 		dev->driver = NULL;
 		dev_set_drvdata(dev, NULL);
@@ -458,6 +476,8 @@ static int really_probe(struct device *dev, struct device_driver *drv)
 pinctrl_bind_failed:
 	device_links_no_driver(dev);
 	devres_release_all(dev);
+	if (do_pm_domain)
+		dev_pm_domain_detach(dev, true);
 	driver_sysfs_remove(dev);
 	dev->driver = NULL;
 	dev_set_drvdata(dev, NULL);
@@ -818,6 +838,7 @@ int driver_attach(struct device_driver *drv)
 static void __device_release_driver(struct device *dev, struct device *parent)
 {
 	struct device_driver *drv;
+	bool do_pm_domain = false;
 
 	drv = dev->driver;
 	if (drv) {
@@ -855,15 +876,19 @@ static void __device_release_driver(struct device *dev, struct device *parent)
 
 		pm_runtime_put_sync(dev);
 
-		if (dev->bus && dev->bus->remove)
+		if (dev->bus && dev->bus->remove) {
 			dev->bus->remove(dev);
-		else if (drv->remove)
+		} else if (drv->remove) {
+			do_pm_domain = true;
 			drv->remove(dev);
+		}
 
 		device_links_driver_cleanup(dev);
 		dma_deconfigure(dev);
 
 		devres_release_all(dev);
+		if (do_pm_domain)
+			dev_pm_domain_detach(dev, true);
 		dev->driver = NULL;
 		dev_set_drvdata(dev, NULL);
 		if (dev->pm_domain && dev->pm_domain->dismiss)
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index d1bd992..8fa688d 100644
--- a/drivers/base/platform.c
+++ b/drivers/base/platform.c
@@ -572,22 +572,8 @@ static int platform_drv_probe(struct device *_dev)
 	if (ret < 0)
 		return ret;
 
-	ret = dev_pm_domain_attach(_dev, true);
-	if (ret != -EPROBE_DEFER) {
-		if (drv->probe) {
-			ret = drv->probe(dev);
-			if (ret)
-				dev_pm_domain_detach(_dev, true);
-		} else {
-			/* don't fail if just dev_pm_domain_attach failed */
-			ret = 0;
-		}
-	}
-
-	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
-		dev_warn(_dev, "probe deferral not supported\n");
-		ret = -ENXIO;
-	}
+	if (drv->probe)
+		ret = drv->probe(dev);
 
 	return ret;
 }
-- 
1.9.1