Commit 2c04d279 authored by Jun Miao's avatar Jun Miao Committed by Jakub Kicinski
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net: usb: Convert tasklet API to new bottom half workqueue mechanism 



Migrate tasklet APIs to the new bottom half workqueue mechanism. It
replaces all occurrences of tasklet usage with the appropriate workqueue
APIs throughout the usbnet driver. This transition ensures compatibility
with the latest design and enhances performance.

Signed-off-by: default avatarJun Miao <jun.miao@intel.com>
Link: https://patch.msgid.link/20250618173923.950510-1-jun.miao@intel.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent deb21a6e

drivers/net/usb/usbnet.c

+18 −18
Original line number Diff line number Diff line
@@ -461,7 +461,7 @@ static enum skb_state defer_bh(struct usbnet *dev, struct sk_buff *skb, 


	__skb_queue_tail(&dev->done, skb);

	if (dev->done.qlen == 1)

		tasklet_schedule(&dev->bh);

		queue_work(system_bh_wq, &dev->bh_work);

	spin_unlock(&dev->done.lock);

	spin_unlock_irqrestore(&list->lock, flags);

	return old_state;
@@ -549,7 +549,7 @@ static int rx_submit (struct usbnet *dev, struct urb *urb, gfp_t flags) 
		default:

			netif_dbg(dev, rx_err, dev->net,

				  "rx submit, %d\n", retval);

			tasklet_schedule (&dev->bh);

			queue_work(system_bh_wq, &dev->bh_work);

			break;

		case 0:

			__usbnet_queue_skb(&dev->rxq, skb, rx_start);
@@ -709,7 +709,7 @@ void usbnet_resume_rx(struct usbnet *dev) 
		num++;

	}



	tasklet_schedule(&dev->bh);

	queue_work(system_bh_wq, &dev->bh_work);



	netif_dbg(dev, rx_status, dev->net,

		  "paused rx queue disabled, %d skbs requeued\n", num);
@@ -778,7 +778,7 @@ void usbnet_unlink_rx_urbs(struct usbnet *dev) 
{

	if (netif_running(dev->net)) {

		(void) unlink_urbs (dev, &dev->rxq);

		tasklet_schedule(&dev->bh);

		queue_work(system_bh_wq, &dev->bh_work);

	}

}

EXPORT_SYMBOL_GPL(usbnet_unlink_rx_urbs);
@@ -861,14 +861,14 @@ int usbnet_stop (struct net_device *net) 
	/* deferred work (timer, softirq, task) must also stop */

	dev->flags = 0;

	timer_delete_sync(&dev->delay);

	tasklet_kill(&dev->bh);

	disable_work_sync(&dev->bh_work);

	cancel_work_sync(&dev->kevent);



	/* We have cyclic dependencies. Those calls are needed

	 * to break a cycle. We cannot fall into the gaps because

	 * we have a flag

	 */

	tasklet_kill(&dev->bh);

	disable_work_sync(&dev->bh_work);

	timer_delete_sync(&dev->delay);

	cancel_work_sync(&dev->kevent);
@@ -955,7 +955,7 @@ int usbnet_open (struct net_device *net) 
	clear_bit(EVENT_RX_KILL, &dev->flags);



	// delay posting reads until we're fully open

	tasklet_schedule (&dev->bh);

	queue_work(system_bh_wq, &dev->bh_work);

	if (info->manage_power) {

		retval = info->manage_power(dev, 1);

		if (retval < 0) {
@@ -1123,7 +1123,7 @@ static void __handle_link_change(struct usbnet *dev) 
		 */

	} else {

		/* submitting URBs for reading packets */

		tasklet_schedule(&dev->bh);

		queue_work(system_bh_wq, &dev->bh_work);

	}



	/* hard_mtu or rx_urb_size may change during link change */
@@ -1198,11 +1198,11 @@ usbnet_deferred_kevent (struct work_struct *work) 
		} else {

			clear_bit (EVENT_RX_HALT, &dev->flags);

			if (!usbnet_going_away(dev))

				tasklet_schedule(&dev->bh);

				queue_work(system_bh_wq, &dev->bh_work);

		}

	}



	/* tasklet could resubmit itself forever if memory is tight */

	/* work could resubmit itself forever if memory is tight */

	if (test_bit (EVENT_RX_MEMORY, &dev->flags)) {

		struct urb	*urb = NULL;

		int resched = 1;
@@ -1224,7 +1224,7 @@ usbnet_deferred_kevent (struct work_struct *work) 
fail_lowmem:

			if (resched)

				if (!usbnet_going_away(dev))

					tasklet_schedule(&dev->bh);

					queue_work(system_bh_wq, &dev->bh_work);

		}

	}
@@ -1325,7 +1325,7 @@ void usbnet_tx_timeout (struct net_device *net, unsigned int txqueue) 
	struct usbnet		*dev = netdev_priv(net);



	unlink_urbs (dev, &dev->txq);

	tasklet_schedule (&dev->bh);

	queue_work(system_bh_wq, &dev->bh_work);

	/* this needs to be handled individually because the generic layer

	 * doesn't know what is sufficient and could not restore private

	 * information if a remedy of an unconditional reset were used.
@@ -1547,7 +1547,7 @@ static inline void usb_free_skb(struct sk_buff *skb) 


/*-------------------------------------------------------------------------*/



// tasklet (work deferred from completions, in_irq) or timer

// work (work deferred from completions, in_irq) or timer



static void usbnet_bh (struct timer_list *t)

{
@@ -1601,16 +1601,16 @@ static void usbnet_bh (struct timer_list *t) 
					  "rxqlen %d --> %d\n",

					  temp, dev->rxq.qlen);

			if (dev->rxq.qlen < RX_QLEN(dev))

				tasklet_schedule (&dev->bh);

				queue_work(system_bh_wq, &dev->bh_work);

		}

		if (dev->txq.qlen < TX_QLEN (dev))

			netif_wake_queue (dev->net);

	}

}



static void usbnet_bh_tasklet(struct tasklet_struct *t)

static void usbnet_bh_work(struct work_struct *work)

{

	struct usbnet *dev = from_tasklet(dev, t, bh);

	struct usbnet *dev = from_work(dev, work, bh_work);



	usbnet_bh(&dev->delay);

}
@@ -1742,7 +1742,7 @@ usbnet_probe (struct usb_interface *udev, const struct usb_device_id *prod) 
	skb_queue_head_init (&dev->txq);

	skb_queue_head_init (&dev->done);

	skb_queue_head_init(&dev->rxq_pause);

	tasklet_setup(&dev->bh, usbnet_bh_tasklet);

	INIT_WORK(&dev->bh_work, usbnet_bh_work);

	INIT_WORK (&dev->kevent, usbnet_deferred_kevent);

	init_usb_anchor(&dev->deferred);

	timer_setup(&dev->delay, usbnet_bh, 0);
@@ -1971,7 +1971,7 @@ int usbnet_resume (struct usb_interface *intf) 


			if (!(dev->txq.qlen >= TX_QLEN(dev)))

				netif_tx_wake_all_queues(dev->net);

			tasklet_schedule (&dev->bh);

			queue_work(system_bh_wq, &dev->bh_work);

		}

	}

include/linux/usb/usbnet.h

+1 −1
Original line number Diff line number Diff line
@@ -58,7 +58,7 @@ struct usbnet { 
	unsigned		interrupt_count;

	struct mutex		interrupt_mutex;

	struct usb_anchor	deferred;

	struct tasklet_struct	bh;

	struct work_struct	bh_work;



	struct work_struct	kevent;

	unsigned long		flags;