4 files changed, 32 insertions, 28 deletions

diff --git a/drivers/i2c/busses/i2c-designware-core.h b/drivers/i2c/busses/i2c-designware-core.h
index 21bf619a86c5..9fee4c054d3d 100644
--- a/drivers/i2c/busses/i2c-designware-core.h
+++ b/drivers/i2c/busses/i2c-designware-core.h
@@ -280,8 +280,6 @@ struct dw_i2c_dev {
 	int			(*acquire_lock)(struct dw_i2c_dev *dev);
 	void			(*release_lock)(struct dw_i2c_dev *dev);
 	bool			pm_disabled;
-	bool			suspended;
-	bool			skip_resume;
 	void			(*disable)(struct dw_i2c_dev *dev);
 	void			(*disable_int)(struct dw_i2c_dev *dev);
 	int			(*init)(struct dw_i2c_dev *dev);
diff --git a/drivers/i2c/busses/i2c-designware-platdrv.c b/drivers/i2c/busses/i2c-designware-platdrv.c
index 58add69a441c..153b947702c5 100644
--- a/drivers/i2c/busses/i2c-designware-platdrv.c
+++ b/drivers/i2c/busses/i2c-designware-platdrv.c
@@ -42,6 +42,7 @@
 #include <linux/reset.h>
 #include <linux/sched.h>
 #include <linux/slab.h>
+#include <linux/suspend.h>
 
 #include "i2c-designware-core.h"
 
@@ -372,6 +373,11 @@ static int dw_i2c_plat_probe(struct platform_device *pdev)
 	ACPI_COMPANION_SET(&adap->dev, ACPI_COMPANION(&pdev->dev));
 	adap->dev.of_node = pdev->dev.of_node;
 
+	dev_pm_set_driver_flags(&pdev->dev,
+				DPM_FLAG_SMART_PREPARE |
+				DPM_FLAG_SMART_SUSPEND |
+				DPM_FLAG_LEAVE_SUSPENDED);
+
 	/* The code below assumes runtime PM to be disabled. */
 	WARN_ON(pm_runtime_enabled(&pdev->dev));
 
@@ -435,12 +441,24 @@ MODULE_DEVICE_TABLE(of, dw_i2c_of_match);
 #ifdef CONFIG_PM_SLEEP
 static int dw_i2c_plat_prepare(struct device *dev)
 {
-	return pm_runtime_suspended(dev);
+	/*
+	 * If the ACPI companion device object is present for this device, it
+	 * may be accessed during suspend and resume of other devices via I2C
+	 * operation regions, so tell the PM core and middle layers to avoid
+	 * skipping system suspend/resume callbacks for it in that case.
+	 */
+	return !has_acpi_companion(dev);
 }
 
 static void dw_i2c_plat_complete(struct device *dev)
 {
-	if (dev->power.direct_complete)
+	/*
+	 * The device can only be in runtime suspend at this point if it has not
+	 * been resumed throughout the ending system suspend/resume cycle, so if
+	 * the platform firmware might mess up with it, request the runtime PM
+	 * framework to resume it.
+	 */
+	if (pm_runtime_suspended(dev) && pm_resume_via_firmware())
 		pm_request_resume(dev);
 }
 #else
@@ -453,16 +471,9 @@ static int dw_i2c_plat_suspend(struct device *dev)
 {
 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 
-	if (i_dev->suspended) {
-		i_dev->skip_resume = true;
-		return 0;
-	}
-
 	i_dev->disable(i_dev);
 	i2c_dw_plat_prepare_clk(i_dev, false);
 
-	i_dev->suspended = true;
-
 	return 0;
 }
 
@@ -470,19 +481,9 @@ static int dw_i2c_plat_resume(struct device *dev)
 {
 	struct dw_i2c_dev *i_dev = dev_get_drvdata(dev);
 
-	if (!i_dev->suspended)
-		return 0;
-
-	if (i_dev->skip_resume) {
-		i_dev->skip_resume = false;
-		return 0;
-	}
-
 	i2c_dw_plat_prepare_clk(i_dev, true);
 	i_dev->init(i_dev);
 
-	i_dev->suspended = false;
-
 	return 0;
 }
 
diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c
index 706164b4c5be..f7829a74140c 100644
--- a/drivers/i2c/i2c-core-base.c
+++ b/drivers/i2c/i2c-core-base.c
@@ -821,8 +821,12 @@ void i2c_unregister_device(struct i2c_client *client)
 {
 	if (!client)
 		return;
-	if (client->dev.of_node)
+
+	if (client->dev.of_node) {
 		of_node_clear_flag(client->dev.of_node, OF_POPULATED);
+		of_node_put(client->dev.of_node);
+	}
+
 	if (ACPI_COMPANION(&client->dev))
 		acpi_device_clear_enumerated(ACPI_COMPANION(&client->dev));
 	device_unregister(&client->dev);
diff --git a/drivers/i2c/i2c-core-smbus.c b/drivers/i2c/i2c-core-smbus.c
index 4bb9927afd01..a1082c04ac5c 100644
--- a/drivers/i2c/i2c-core-smbus.c
+++ b/drivers/i2c/i2c-core-smbus.c
@@ -397,16 +397,17 @@ static s32 i2c_smbus_xfer_emulated(struct i2c_adapter *adapter, u16 addr,
 				   the underlying bus driver */
 		break;
 	case I2C_SMBUS_I2C_BLOCK_DATA:
+		if (data->block[0] > I2C_SMBUS_BLOCK_MAX) {
+			dev_err(&adapter->dev, "Invalid block %s size %d\n",
+				read_write == I2C_SMBUS_READ ? "read" : "write",
+				data->block[0]);
+			return -EINVAL;
+		}
+
 		if (read_write == I2C_SMBUS_READ) {
 			msg[1].len = data->block[0];
 		} else {
 			msg[0].len = data->block[0] + 1;
-			if (msg[0].len > I2C_SMBUS_BLOCK_MAX + 1) {
-				dev_err(&adapter->dev,
-					"Invalid block write size %d\n",
-					data->block[0]);
-				return -EINVAL;
-			}
 			for (i = 1; i <= data->block[0]; i++)
 				msgbuf0[i] = data->block[i];
 		}