From 776ac63a986d211286230c4fd70f85390eabedcd Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@suse.de>
Date: Wed, 14 Jul 2021 19:00:22 +0200
Subject: [PATCH] r8152: Fix a deadlock by doubly PM resume
Git-commit: 776ac63a986d211286230c4fd70f85390eabedcd
Patch-mainline: v5.14-rc3
References: bsc#1186194

r8152 driver sets up the MAC address at reset-resume, while
rtl8152_set_mac_address() has the temporary autopm get/put.  This may
lead to a deadlock as the PM lock has been already taken for the
execution of the runtime PM callback.

This patch adds the workaround to avoid the superfluous autpm when
called from rtl8152_reset_resume().

Link: https://bugzilla.suse.com/show_bug.cgi?id=1186194
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

---
 drivers/net/usb/r8152.c |   27 ++++++++++++++++++---------
 1 file changed, 18 insertions(+), 9 deletions(-)

--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -1157,7 +1157,8 @@ void write_mii_word(struct net_device *n
 static int
 r8152_submit_rx(struct r8152 *tp, struct rx_agg *agg, gfp_t mem_flags);
 
-static int rtl8152_set_mac_address(struct net_device *netdev, void *p)
+static int __rtl8152_set_mac_address(struct net_device *netdev, void *p,
+				     bool in_resume)
 {
 	struct r8152 *tp = netdev_priv(netdev);
 	struct sockaddr *addr = p;
@@ -1166,9 +1167,11 @@ static int rtl8152_set_mac_address(struc
 	if (!is_valid_ether_addr(addr->sa_data))
 		goto out1;
 
-	ret = usb_autopm_get_interface(tp->intf);
-	if (ret < 0)
-		goto out1;
+	if (!in_resume) {
+		ret = usb_autopm_get_interface(tp->intf);
+		if (ret < 0)
+			goto out1;
+	}
 
 	mutex_lock(&tp->control);
 
@@ -1180,11 +1183,17 @@ static int rtl8152_set_mac_address(struc
 
 	mutex_unlock(&tp->control);
 
-	usb_autopm_put_interface(tp->intf);
+	if (!in_resume)
+		usb_autopm_put_interface(tp->intf);
 out1:
 	return ret;
 }
 
+static int rtl8152_set_mac_address(struct net_device *netdev, void *p)
+{
+	return __rtl8152_set_mac_address(netdev, p, false);
+}
+
 /* Devices containing proper chips can support a persistent
  * host system provided MAC address.
  * Examples of this are Dell TB15 and Dell WD15 docks
@@ -1285,7 +1294,7 @@ static int determine_ethernet_addr(struc
 	return ret;
 }
 
-static int set_ethernet_addr(struct r8152 *tp)
+static int set_ethernet_addr(struct r8152 *tp, bool in_resume)
 {
 	struct net_device *dev = tp->netdev;
 	struct sockaddr sa;
@@ -1298,7 +1307,7 @@ static int set_ethernet_addr(struct r815
 	if (tp->version == RTL_VER_01)
 		ether_addr_copy(dev->dev_addr, sa.sa_data);
 	else
-		ret = rtl8152_set_mac_address(dev, &sa);
+		ret = __rtl8152_set_mac_address(dev, &sa, in_resume);
 
 	return ret;
 }
@@ -4595,7 +4604,7 @@ static int rtl8152_reset_resume(struct u
 	clear_bit(SELECTIVE_SUSPEND, &tp->flags);
 	tp->rtl_ops.init(tp);
 	queue_delayed_work(system_long_wq, &tp->hw_phy_work, 0);
-	set_ethernet_addr(tp);
+	set_ethernet_addr(tp, true);
 	return rtl8152_resume(intf);
 }
 
@@ -5394,7 +5403,7 @@ static int rtl8152_probe(struct usb_inte
 
 	tp->rtl_ops.init(tp);
 	queue_delayed_work(system_long_wq, &tp->hw_phy_work, 0);
-	set_ethernet_addr(tp);
+	set_ethernet_addr(tp, false);
 
 	usb_set_intfdata(intf, tp);
 	netif_napi_add(netdev, &tp->napi, r8152_poll, RTL8152_NAPI_WEIGHT);