2019-08-26 08:50:53

by Hayes Wang

Subject: [PATCH net v2 0/2] r8152: fix side effect

v2:
Replace patch #2 with "r8152: remove calling netif_napi_del".

v1:
The commit 0ee1f4734967 ("r8152: napi hangup fix after disconnect")
add a check to avoid using napi_disable after netif_napi_del. However,
the commit ffa9fec30ca0 ("r8152: set RTL8152_UNPLUG only for real
disconnection") let the check useless.

Therefore, I revert commit 0ee1f4734967 ("r8152: napi hangup fix
after disconnect") first, and add another patch to fix it.

Hayes Wang (2):
Revert "r8152: napi hangup fix after disconnect"
r8152: remove calling netif_napi_del

drivers/net/usb/r8152.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

--
2.21.0

2019-08-26 08:52:47

by Hayes Wang

Subject: [PATCH net v2 1/2] Revert "r8152: napi hangup fix after disconnect"

This reverts commit 0ee1f4734967af8321ecebaf9c74221ace34f2d5.

This conflicts with commit ffa9fec30ca0 ("r8152: set
RTL8152_UNPLUG only for real disconnection").

Signed-off-by: Hayes Wang <[email protected]>
---
drivers/net/usb/r8152.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index eee0f5007ee3..ad3abe26b51b 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -4021,8 +4021,7 @@ static int rtl8152_close(struct net_device *netdev)
#ifdef CONFIG_PM_SLEEP
unregister_pm_notifier(&tp->pm_notifier);
#endif
- if (!test_bit(RTL8152_UNPLUG, &tp->flags))
- napi_disable(&tp->napi);
+ napi_disable(&tp->napi);
clear_bit(WORK_ENABLE, &tp->flags);
usb_kill_urb(tp->intr_urb);
cancel_delayed_work_sync(&tp->schedule);
--
2.21.0

2019-08-26 10:19:14

by Hayes Wang

Subject: RE: [PATCH net v2 1/2] Revert "r8152: napi hangup fix after disconnect"

Jiri Slaby [mailto:[email protected]]
> Sent: Monday, August 26, 2019 4:55 PM
[...]
> Could you clarify *why* it conflicts? And how is the problem fixed by
> 0ee1f473496 avoided now?

In rtl8152_disconnect(), the flow would be as following.

static void rtl8152_disconnect(struct usb_interface *intf)
{
...
- netif_napi_del(&tp->napi);
- unregister_netdev(tp->netdev);
- rtl8152_close
- napi_disable

Therefore you add a checking of RTL8152_UNPLUG to avoid
calling napi_disable() after netif_napi_del(). However,
after commit ffa9fec30ca0 ("r8152: set RTL8152_UNPLUG
only for real disconnection"), RTL8152_UNPLUG is not
always set when calling rtl8152_disconnect(). That is,
napi_disable() would be called after netif_napi_del(),
if RTL8152_UNPLUG is not set.

The best way is to avoid calling netif_napi_del() before
calling unregister_netdev(). And I has submitted such
patch following this one.

Best Regards,
Hayes

2019-08-26 11:16:59

by Jiri Slaby

Subject: Re: [PATCH net v2 1/2] Revert "r8152: napi hangup fix after disconnect"

On 26. 08. 19, 10:41, Hayes Wang wrote:
> This reverts commit 0ee1f4734967af8321ecebaf9c74221ace34f2d5.
>
> This conflicts with commit ffa9fec30ca0 ("r8152: set
> RTL8152_UNPLUG only for real disconnection").

Could you clarify *why* it conflicts? And how is the problem fixed by
0ee1f473496 avoided now?

> Signed-off-by: Hayes Wang <[email protected]>
> ---
> drivers/net/usb/r8152.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index eee0f5007ee3..ad3abe26b51b 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -4021,8 +4021,7 @@ static int rtl8152_close(struct net_device *netdev)
> #ifdef CONFIG_PM_SLEEP
> unregister_pm_notifier(&tp->pm_notifier);
> #endif
> - if (!test_bit(RTL8152_UNPLUG, &tp->flags))
> - napi_disable(&tp->napi);
> + napi_disable(&tp->napi);
> clear_bit(WORK_ENABLE, &tp->flags);
> usb_kill_urb(tp->intr_urb);
> cancel_delayed_work_sync(&tp->schedule);
>

thanks,
--
js
suse labs

2019-08-26 21:53:14

by David Miller

Subject: Re: [PATCH net v2 1/2] Revert "r8152: napi hangup fix after disconnect"

From: Hayes Wang <[email protected]>
Date: Mon, 26 Aug 2019 09:43:32 +0000

> Jiri Slaby [mailto:[email protected]]
>> Sent: Monday, August 26, 2019 4:55 PM
> [...]
>> Could you clarify *why* it conflicts? And how is the problem fixed by
>> 0ee1f473496 avoided now?
>
> In rtl8152_disconnect(), the flow would be as following.
>
> static void rtl8152_disconnect(struct usb_interface *intf)
> {
> ...
> - netif_napi_del(&tp->napi);
> - unregister_netdev(tp->netdev);
> - rtl8152_close
> - napi_disable
>
> Therefore you add a checking of RTL8152_UNPLUG to avoid
> calling napi_disable() after netif_napi_del(). However,
> after commit ffa9fec30ca0 ("r8152: set RTL8152_UNPLUG
> only for real disconnection"), RTL8152_UNPLUG is not
> always set when calling rtl8152_disconnect(). That is,
> napi_disable() would be called after netif_napi_del(),
> if RTL8152_UNPLUG is not set.
>
> The best way is to avoid calling netif_napi_del() before
> calling unregister_netdev(). And I has submitted such
> patch following this one.

These details belong in the commit message, always.