Patch "r8169: fix deadlock on RTL8125 in jumbo mtu mode" has been added to the 6.1-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    r8169: fix deadlock on RTL8125 in jumbo mtu mode

to the 6.1-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     r8169-fix-deadlock-on-rtl8125-in-jumbo-mtu-mode.patch
and it can be found in the queue-6.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit ed7cb964af5d7f9eb9e14ce8d75624756f51e2d5
Author: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Date:   Sun Nov 26 19:36:46 2023 +0100

    r8169: fix deadlock on RTL8125 in jumbo mtu mode
    
    [ Upstream commit 59d395ed606d8df14615712b0cdcdadb2d962175 ]
    
    The original change results in a deadlock if jumbo mtu mode is used.
    Reason is that the phydev lock is held when rtl_reset_work() is called
    here, and rtl_jumbo_config() calls phy_start_aneg() which also tries
    to acquire the phydev lock. Fix this by calling rtl_reset_work()
    asynchronously.
    
    Fixes: 621735f59064 ("r8169: fix rare issue with broken rx after link-down on RTL8125")
    Reported-by: Ian Chen <free122448@xxxxxxxxxxx>
    Tested-by: Ian Chen <free122448@xxxxxxxxxxx>
    Cc: stable@xxxxxxxxxxxxxxx
    Signed-off-by: Heiner Kallweit <hkallweit1@xxxxxxxxx>
    Link: https://lore.kernel.org/r/caf6a487-ef8c-4570-88f9-f47a659faf33@xxxxxxxxx
    Signed-off-by: Paolo Abeni <pabeni@xxxxxxxxxx>
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index 7cb09ba14533c..abfa375b08878 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -576,6 +576,7 @@ struct rtl8169_tc_offsets {
 enum rtl_flag {
 	RTL_FLAG_TASK_ENABLED = 0,
 	RTL_FLAG_TASK_RESET_PENDING,
+	RTL_FLAG_TASK_RESET_NO_QUEUE_WAKE,
 	RTL_FLAG_TASK_TX_TIMEOUT,
 	RTL_FLAG_MAX
 };
@@ -4559,6 +4560,8 @@ static void rtl_task(struct work_struct *work)
 reset:
 		rtl_reset_work(tp);
 		netif_wake_queue(tp->dev);
+	} else if (test_and_clear_bit(RTL_FLAG_TASK_RESET_NO_QUEUE_WAKE, tp->wk.flags)) {
+		rtl_reset_work(tp);
 	}
 out_unlock:
 	rtnl_unlock();
@@ -4592,7 +4595,7 @@ static void r8169_phylink_handler(struct net_device *ndev)
 	} else {
 		/* In few cases rx is broken after link-down otherwise */
 		if (rtl_is_8125(tp))
-			rtl_reset_work(tp);
+			rtl_schedule_task(tp, RTL_FLAG_TASK_RESET_NO_QUEUE_WAKE);
 		pm_runtime_idle(d);
 	}