[PATCH 5.15 119/136] Revert "usbnet: smsc95xx: Fix deadlock on runtime resume"

[Greg Kroah-Hartman]

From: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

This reverts commit b574d1e3e9a2432b5acd9c4a9dc8d70b6a37aaf1 which is
commit 7b960c967f2aa01ab8f45c5a0bd78e754cffdeee upstream.

It is reported to cause problems, so drop it from the 5.15.y tree until
the root cause can be determined.

Reported-by: Lukas Wunner <lukas@xxxxxxxxx>
Cc: Oleksij Rempel <o.rempel@xxxxxxxxxxxxxx>
Cc: Ferry Toth <fntoth@xxxxxxxxx>
Cc: Andrew Lunn <andrew@xxxxxxx>
Cc: Andre Edich <andre.edich@xxxxxxxxxxxxx>
Cc: David S. Miller <davem@xxxxxxxxxxxxx>
Cc: Sasha Levin <sashal@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20220826132137.GA24932@xxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/net/usb/smsc95xx.c |   26 ++++++--------------------
 1 file changed, 6 insertions(+), 20 deletions(-)

--- a/drivers/net/usb/smsc95xx.c
+++ b/drivers/net/usb/smsc95xx.c
@@ -69,7 +69,6 @@ struct smsc95xx_priv {
 	struct fwnode_handle *irqfwnode;
 	struct mii_bus *mdiobus;
 	struct phy_device *phydev;
-	struct task_struct *pm_task;
 };
 
 static bool turbo_mode = true;
@@ -79,14 +78,13 @@ MODULE_PARM_DESC(turbo_mode, "Enable mul
 static int __must_check __smsc95xx_read_reg(struct usbnet *dev, u32 index,
 					    u32 *data, int in_pm)
 {
-	struct smsc95xx_priv *pdata = dev->driver_priv;
 	u32 buf;
 	int ret;
 	int (*fn)(struct usbnet *, u8, u8, u16, u16, void *, u16);
 
 	BUG_ON(!dev);
 
-	if (current != pdata->pm_task)
+	if (!in_pm)
 		fn = usbnet_read_cmd;
 	else
 		fn = usbnet_read_cmd_nopm;
@@ -110,14 +108,13 @@ static int __must_check __smsc95xx_read_
 static int __must_check __smsc95xx_write_reg(struct usbnet *dev, u32 index,
 					     u32 data, int in_pm)
 {
-	struct smsc95xx_priv *pdata = dev->driver_priv;
 	u32 buf;
 	int ret;
 	int (*fn)(struct usbnet *, u8, u8, u16, u16, const void *, u16);
 
 	BUG_ON(!dev);
 
-	if (current != pdata->pm_task)
+	if (!in_pm)
 		fn = usbnet_write_cmd;
 	else
 		fn = usbnet_write_cmd_nopm;
@@ -1485,12 +1482,9 @@ static int smsc95xx_suspend(struct usb_i
 	u32 val, link_up;
 	int ret;
 
-	pdata->pm_task = current;
-
 	ret = usbnet_suspend(intf, message);
 	if (ret < 0) {
 		netdev_warn(dev->net, "usbnet_suspend error\n");
-		pdata->pm_task = NULL;
 		return ret;
 	}
 
@@ -1730,7 +1724,6 @@ done:
 	if (ret && PMSG_IS_AUTO(message))
 		usbnet_resume(intf);
 
-	pdata->pm_task = NULL;
 	return ret;
 }
 
@@ -1751,31 +1744,29 @@ static int smsc95xx_resume(struct usb_in
 	/* do this first to ensure it's cleared even in error case */
 	pdata->suspend_flags = 0;
 
-	pdata->pm_task = current;
-
 	if (suspend_flags & SUSPEND_ALLMODES) {
 		/* clear wake-up sources */
 		ret = smsc95xx_read_reg_nopm(dev, WUCSR, &val);
 		if (ret < 0)
-			goto done;
+			return ret;
 
 		val &= ~(WUCSR_WAKE_EN_ | WUCSR_MPEN_);
 
 		ret = smsc95xx_write_reg_nopm(dev, WUCSR, val);
 		if (ret < 0)
-			goto done;
+			return ret;
 
 		/* clear wake-up status */
 		ret = smsc95xx_read_reg_nopm(dev, PM_CTRL, &val);
 		if (ret < 0)
-			goto done;
+			return ret;
 
 		val &= ~PM_CTL_WOL_EN_;
 		val |= PM_CTL_WUPS_;
 
 		ret = smsc95xx_write_reg_nopm(dev, PM_CTRL, val);
 		if (ret < 0)
-			goto done;
+			return ret;
 	}
 
 	phy_init_hw(pdata->phydev);
@@ -1784,20 +1775,15 @@ static int smsc95xx_resume(struct usb_in
 	if (ret < 0)
 		netdev_warn(dev->net, "usbnet_resume error\n");
 
-done:
-	pdata->pm_task = NULL;
 	return ret;
 }
 
 static int smsc95xx_reset_resume(struct usb_interface *intf)
 {
 	struct usbnet *dev = usb_get_intfdata(intf);
-	struct smsc95xx_priv *pdata = dev->driver_priv;
 	int ret;
 
-	pdata->pm_task = current;
 	ret = smsc95xx_reset(dev);
-	pdata->pm_task = NULL;
 	if (ret < 0)
 		return ret;