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Commit eea423aa authored by Ahmed S. Darwish's avatar Ahmed S. Darwish Committed by Greg Kroah-Hartman
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net: arcnet: Fix RESET flag handling 



[ Upstream commit 01365633bd1c836240f9bbf86bbeee749795480a ]

The main arcnet interrupt handler calls arcnet_close() then
arcnet_open(), if the RESET status flag is encountered.

This is invalid:

  1) In general, interrupt handlers should never call ->ndo_stop() and
     ->ndo_open() functions. They are usually full of blocking calls and
     other methods that are expected to be called only from drivers
     init and exit code paths.

  2) arcnet_close() contains a del_timer_sync(). If the irq handler
     interrupts the to-be-deleted timer, del_timer_sync() will just loop
     forever.

  3) arcnet_close() also calls tasklet_kill(), which has a warning if
     called from irq context.

  4) For device reset, the sequence "arcnet_close(); arcnet_open();" is
     not complete.  Some children arcnet drivers have special init/exit
     code sequences, which then embed a call to arcnet_open() and
     arcnet_close() accordingly. Check drivers/net/arcnet/com20020.c.

Run the device RESET sequence from a scheduled workqueue instead.

Signed-off-by: default avatarAhmed S. Darwish <a.darwish@linutronix.de>
Signed-off-by: default avatarSebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20210128194802.727770-1-a.darwish@linutronix.de


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Stable-dep-of: 6b17a597fc2f ("arcnet: restoring support for multiple Sohard Arcnet cards")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 36192fc0

drivers/net/arcnet/arc-rimi.c

+2 −2
Original line number Diff line number Diff line
@@ -332,7 +332,7 @@ static int __init arc_rimi_init(void) 
		dev->irq = 9;



	if (arcrimi_probe(dev)) {

		free_netdev(dev);

		free_arcdev(dev);

		return -EIO;

	}
@@ -349,7 +349,7 @@ static void __exit arc_rimi_exit(void) 
	iounmap(lp->mem_start);

	release_mem_region(dev->mem_start, dev->mem_end - dev->mem_start + 1);

	free_irq(dev->irq, dev);

	free_netdev(dev);

	free_arcdev(dev);

}



#ifndef MODULE

drivers/net/arcnet/arcdevice.h

+6 −0
Original line number Diff line number Diff line
@@ -303,6 +303,10 @@ struct arcnet_local { 


	int excnak_pending;    /* We just got an excesive nak interrupt */



	/* RESET flag handling */

	int reset_in_progress;

	struct work_struct reset_work;



	struct {

		uint16_t sequence;	/* sequence number (incs with each packet) */

		__be16 aborted_seq;
@@ -355,7 +359,9 @@ void arcnet_dump_skb(struct net_device *dev, struct sk_buff *skb, char *desc) 


void arcnet_unregister_proto(struct ArcProto *proto);

irqreturn_t arcnet_interrupt(int irq, void *dev_id);



struct net_device *alloc_arcdev(const char *name);

void free_arcdev(struct net_device *dev);



int arcnet_open(struct net_device *dev);

int arcnet_close(struct net_device *dev);

drivers/net/arcnet/arcnet.c

+62 −4
Original line number Diff line number Diff line
@@ -387,10 +387,44 @@ static void arcnet_timer(struct timer_list *t) 
	struct arcnet_local *lp = from_timer(lp, t, timer);

	struct net_device *dev = lp->dev;



	if (!netif_carrier_ok(dev)) {

	spin_lock_irq(&lp->lock);



	if (!lp->reset_in_progress && !netif_carrier_ok(dev)) {

		netif_carrier_on(dev);

		netdev_info(dev, "link up\n");

	}



	spin_unlock_irq(&lp->lock);

}



static void reset_device_work(struct work_struct *work)

{

	struct arcnet_local *lp;

	struct net_device *dev;



	lp = container_of(work, struct arcnet_local, reset_work);

	dev = lp->dev;



	/* Do not bring the network interface back up if an ifdown

	 * was already done.

	 */

	if (!netif_running(dev) || !lp->reset_in_progress)

		return;



	rtnl_lock();



	/* Do another check, in case of an ifdown that was triggered in

	 * the small race window between the exit condition above and

	 * acquiring RTNL.

	 */

	if (!netif_running(dev) || !lp->reset_in_progress)

		goto out;



	dev_close(dev);

	dev_open(dev);



out:

	rtnl_unlock();

}



static void arcnet_reply_tasklet(unsigned long data)
@@ -452,12 +486,25 @@ struct net_device *alloc_arcdev(const char *name) 
		lp->dev = dev;

		spin_lock_init(&lp->lock);

		timer_setup(&lp->timer, arcnet_timer, 0);

		INIT_WORK(&lp->reset_work, reset_device_work);

	}



	return dev;

}

EXPORT_SYMBOL(alloc_arcdev);



void free_arcdev(struct net_device *dev)

{

	struct arcnet_local *lp = netdev_priv(dev);



	/* Do not cancel this at ->ndo_close(), as the workqueue itself

	 * indirectly calls the ifdown path through dev_close().

	 */

	cancel_work_sync(&lp->reset_work);

	free_netdev(dev);

}

EXPORT_SYMBOL(free_arcdev);



/* Open/initialize the board.  This is called sometime after booting when

 * the 'ifconfig' program is run.

 *
@@ -587,6 +634,10 @@ int arcnet_close(struct net_device *dev) 


	/* shut down the card */

	lp->hw.close(dev);



	/* reset counters */

	lp->reset_in_progress = 0;



	module_put(lp->hw.owner);

	return 0;

}
@@ -820,6 +871,9 @@ irqreturn_t arcnet_interrupt(int irq, void *dev_id) 


	spin_lock_irqsave(&lp->lock, flags);



	if (lp->reset_in_progress)

		goto out;



	/* RESET flag was enabled - if device is not running, we must

	 * clear it right away (but nothing else).

	 */
@@ -852,11 +906,14 @@ irqreturn_t arcnet_interrupt(int irq, void *dev_id) 
		if (status & RESETflag) {

			arc_printk(D_NORMAL, dev, "spurious reset (status=%Xh)\n",

				   status);

			arcnet_close(dev);

			arcnet_open(dev);



			lp->reset_in_progress = 1;

			netif_stop_queue(dev);

			netif_carrier_off(dev);

			schedule_work(&lp->reset_work);



			/* get out of the interrupt handler! */

			break;

			goto out;

		}

		/* RX is inhibited - we must have received something.

		 * Prepare to receive into the next buffer.
@@ -1052,6 +1109,7 @@ irqreturn_t arcnet_interrupt(int irq, void *dev_id) 
	udelay(1);

	lp->hw.intmask(dev, lp->intmask);



out:

	spin_unlock_irqrestore(&lp->lock, flags);

	return retval;

}

drivers/net/arcnet/com20020-isa.c

+2 −2
Original line number Diff line number Diff line
@@ -169,7 +169,7 @@ static int __init com20020_init(void) 
		dev->irq = 9;



	if (com20020isa_probe(dev)) {

		free_netdev(dev);

		free_arcdev(dev);

		return -EIO;

	}
@@ -182,7 +182,7 @@ static void __exit com20020_exit(void) 
	unregister_netdev(my_dev);

	free_irq(my_dev->irq, my_dev);

	release_region(my_dev->base_addr, ARCNET_TOTAL_SIZE);

	free_netdev(my_dev);

	free_arcdev(my_dev);

}



#ifndef MODULE

drivers/net/arcnet/com20020-pci.c

+1 −1
Original line number Diff line number Diff line
@@ -294,7 +294,7 @@ static void com20020pci_remove(struct pci_dev *pdev) 


		unregister_netdev(dev);

		free_irq(dev->irq, dev);

		free_netdev(dev);

		free_arcdev(dev);

	}

}