[PATCH] r8152: stop submitting rx for -EPROTO

[Jason-ch Chen]

On Thu, 2021-09-30 at 02:41 +0000, Hayes Wang wrote:
> Jason-ch Chen <jason-ch.chen at mediatek.com>
> > Sent: Wednesday, September 29, 2021 5:53 PM
> 
> [...]
> > Hi Hayes,
> > 
> > Sometimes Rx submits rapidly and the USB kernel driver of
> > opensource
> > cannot receive any disconnect event due to CPU heavy loading, which
> > finally causes a system crash.
> > Do you have any suggestions to modify the r8152 driver to prevent
> > this
> > situation happened?
> 
> Do you mind to try the following patch?
> It avoids to re-submit RX immediately.
> 
> diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
> index 60ba9b734055..bfe00af8283f 100644
> --- a/drivers/net/usb/r8152.c
> +++ b/drivers/net/usb/r8152.c
> @@ -767,6 +767,7 @@ enum rtl8152_flags {
>  	PHY_RESET,
>  	SCHEDULE_TASKLET,
>  	GREEN_ETHERNET,
> +	SCHEDULE_NAPI,
>  };
>  
>  #define DEVICE_ID_THINKPAD_THUNDERBOLT3_DOCK_GEN2	0x3082
> @@ -1770,6 +1771,14 @@ static void read_bulk_callback(struct urb
> *urb)
>  		rtl_set_unplug(tp);
>  		netif_device_detach(tp->netdev);
>  		return;
> +	case -EPROTO:
> +		urb->actual_length = 0;
> +		spin_lock_irqsave(&tp->rx_lock, flags);
> +		list_add_tail(&agg->list, &tp->rx_done);
> +		spin_unlock_irqrestore(&tp->rx_lock, flags);
> +		set_bit(SCHEDULE_NAPI, &tp->flags);
> +		schedule_delayed_work(&tp->schedule, 1);
> +		return;
>  	case -ENOENT:
>  		return;	/* the urb is in unlink state */
>  	case -ETIME:
> @@ -2425,6 +2434,7 @@ static int rx_bottom(struct r8152 *tp, int
> budget)
>  	if (list_empty(&tp->rx_done))
>  		goto out1;
>  
> +	clear_bit(SCHEDULE_NAPI, &tp->flags);
>  	INIT_LIST_HEAD(&rx_queue);
>  	spin_lock_irqsave(&tp->rx_lock, flags);
>  	list_splice_init(&tp->rx_done, &rx_queue);
> @@ -2441,7 +2451,7 @@ static int rx_bottom(struct r8152 *tp, int
> budget)
>  
>  		agg = list_entry(cursor, struct rx_agg, list);
>  		urb = agg->urb;
> -		if (urb->actual_length < ETH_ZLEN)
> +		if (urb->status != 0 || urb->actual_length < ETH_ZLEN)
>  			goto submit;
>  
>  		agg_free = rtl_get_free_rx(tp, GFP_ATOMIC);
> @@ -6643,6 +6653,10 @@ static void rtl_work_func_t(struct work_struct
> *work)
>  	    netif_carrier_ok(tp->netdev))
>  		tasklet_schedule(&tp->tx_tl);
>  
> +	if (test_and_clear_bit(SCHEDULE_NAPI, &tp->flags) &&
> +	    !list_empty(&tp->rx_done))
> +		napi_schedule(&tp->napi);
> +
>  	mutex_unlock(&tp->control);
>  
>  out1:
> 
> 
> Best Regards,
> Hayes

Hi,

This patch has been verified.
It did avoid Rx re-submit immediately.

Thanks,
Jason