RE: [PATCH] r8152: stop submitting rx for -EPROTO

[Hayes Wang]

Jason-ch Chen <jason-ch.chen@xxxxxxxxxxxx>
> 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