[PATCHv2] net: usb: r8152: fix resume reset deadlock

[PATCHv2] net: usb: r8152: fix resume reset deadlock

[Sergey Senozhatsky]

rtl8152 can trigger device reset during reset which
potentially can result in a deadlock:

 **** DPM device timeout after 10 seconds; 15 seconds until panic ****
 Call Trace:
 <TASK>
 schedule+0x483/0x1370
 schedule_preempt_disabled+0x15/0x30
 __mutex_lock_common+0x1fd/0x470
 __rtl8152_set_mac_address+0x80/0x1f0
 dev_set_mac_address+0x7f/0x150
 rtl8152_post_reset+0x72/0x150
 usb_reset_device+0x1d0/0x220
 rtl8152_resume+0x99/0xc0
 usb_resume_interface+0x3e/0xc0
 usb_resume_both+0x104/0x150
 usb_resume+0x22/0x110

The problem is that rtl8152 resume calls reset under
tp->control mutex while reset basically re-enters rtl8152
and attempts to acquire the same tp->control lock once
again.

Reset INACCESSIBLE device outside of tp->control mutex
scope to avoid recursive mutex_lock() deadlock.

Fixes: 4933b066fefb ("r8152: If inaccessible at resume time, issue a reset")
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org>
---

v1 -> v2:
- incorporated review feedback from Doug

 drivers/net/usb/r8152.c | 29 +++++++++++++++--------------
 1 file changed, 15 insertions(+), 14 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 30f937527cd2..5e556e26c682 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -8538,19 +8538,6 @@ static int rtl8152_system_resume(struct r8152 *tp)
 		usb_submit_urb(tp->intr_urb, GFP_NOIO);
 	}
 
-	/* If the device is RTL8152_INACCESSIBLE here then we should do a
-	 * reset. This is important because the usb_lock_device_for_reset()
-	 * that happens as a result of usb_queue_reset_device() will silently
-	 * fail if the device was suspended or if too much time passed.
-	 *
-	 * NOTE: The device is locked here so we can directly do the reset.
-	 * We don't need usb_lock_device_for_reset() because that's just a
-	 * wrapper over device_lock() and device_resume() (which calls us)
-	 * does that for us.
-	 */
-	if (test_bit(RTL8152_INACCESSIBLE, &tp->flags))
-		usb_reset_device(tp->udev);
-
 	return 0;
 }
 
@@ -8661,19 +8648,33 @@ static int rtl8152_suspend(struct usb_interface *intf, pm_message_t message)
 static int rtl8152_resume(struct usb_interface *intf)
 {
 	struct r8152 *tp = usb_get_intfdata(intf);
+	bool runtime_resume = test_bit(SELECTIVE_SUSPEND, &tp->flags);
 	int ret;
 
 	mutex_lock(&tp->control);
 
 	rtl_reset_ocp_base(tp);
 
-	if (test_bit(SELECTIVE_SUSPEND, &tp->flags))
+	if (runtime_resume)
 		ret = rtl8152_runtime_resume(tp);
 	else
 		ret = rtl8152_system_resume(tp);
 
 	mutex_unlock(&tp->control);
 
+	/* If the device is RTL8152_INACCESSIBLE here then we should do a
+	 * reset. This is important because the usb_lock_device_for_reset()
+	 * that happens as a result of usb_queue_reset_device() will silently
+	 * fail if the device was suspended or if too much time passed.
+	 *
+	 * NOTE: The device is locked here so we can directly do the reset.
+	 * We don't need usb_lock_device_for_reset() because that's just a
+	 * wrapper over device_lock() and device_resume() (which calls us)
+	 * does that for us.
+	 */
+	if (!runtime_resume && test_bit(RTL8152_INACCESSIBLE, &tp->flags))
+		usb_reset_device(tp->udev);
+
 	return ret;
 }
 
-- 
2.53.0.rc1.217.geba53bf80e-goog

Re: [PATCHv2] net: usb: r8152: fix resume reset deadlock

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by Jakub Kicinski <kuba@kernel.org>:

On Thu, 29 Jan 2026 12:10:30 +0900 you wrote:
> rtl8152 can trigger device reset during reset which
> potentially can result in a deadlock:
> 
>  **** DPM device timeout after 10 seconds; 15 seconds until panic ****
>  Call Trace:
>  <TASK>
>  schedule+0x483/0x1370
>  schedule_preempt_disabled+0x15/0x30
>  __mutex_lock_common+0x1fd/0x470
>  __rtl8152_set_mac_address+0x80/0x1f0
>  dev_set_mac_address+0x7f/0x150
>  rtl8152_post_reset+0x72/0x150
>  usb_reset_device+0x1d0/0x220
>  rtl8152_resume+0x99/0xc0
>  usb_resume_interface+0x3e/0xc0
>  usb_resume_both+0x104/0x150
>  usb_resume+0x22/0x110
> 
> [...]

Here is the summary with links:
  - [PATCHv2] net: usb: r8152: fix resume reset deadlock
    https://git.kernel.org/netdev/net/c/6d06bc83a5ae

You are awesome, thank you!
-- 
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