Re: net: usb: r8152: resume-reset deadlock
From: Sergey Senozhatsky <senozhatsky@chromium.org>
Date: 2026-01-28 06:40:03
Also in:
linux-usb, lkml
Subsystem:
networking drivers, the rest, usb networking drivers · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
On (26/01/28 15:12), Sergey Senozhatsky wrote:
quoted hunk ↗ jump to hunk
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c index 30f937527cd2..c9406b89bb12 100644 --- a/drivers/net/usb/r8152.c +++ b/drivers/net/usb/r8152.c@@ -8538,20 +8538,18 @@ static int rtl8152_system_resume(struct r8152 *tp) usb_submit_urb(tp->intr_urb, GFP_NOIO); } + if (!test_bit(RTL8152_INACCESSIBLE, &tp->flags)) + return 0; + /* 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); + if (test_bit(SELECTIVE_SUSPEND, &tp->flags)) + return usb_reset_device(tp->udev); - return 0; + return -ENODEV; } static int rtl8152_runtime_suspend(struct r8152 *tp)@@ -8674,6 +8672,14 @@ static int rtl8152_resume(struct usb_interface *intf) mutex_unlock(&tp->control); + /* + * This only happens for !SELECTIVE_SUSPEND and RTL8152_INACCESSIBLE, + * drop tp->control, becuase reset can re-acquire it (e.g. from + * max address reset) + */ + if (ret == -ENODEV) + ret = usb_reset_device(tp->udev); + return ret; }
That's too messy. Something like this should be better, I guess: ---
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 30f937527cd2..2cbc07b7aab5 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; }
@@ -8661,6 +8648,7 @@ 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 system_resume = !test_bit(SELECTIVE_SUSPEND, &tp->flags); int ret; mutex_lock(&tp->control);
@@ -8674,6 +8662,9 @@ static int rtl8152_resume(struct usb_interface *intf) mutex_unlock(&tp->control); + if (system_resume && test_bit(RTL8152_INACCESSIBLE, &tp->flags)) + ret = usb_reset_device(tp->udev); + return ret; }