We have started locking the Net device chain - arcnet fix.

David Woodhouse (Dave@imladris.demon.co.uk)
Sun, 07 Jun 1998 12:51:33 +0100

Dave@imladris.demon.co.uk said:
> and my current suspicion is that someone's introduced a lock on the
> device structure, and that lock is already held when the device open
> routine is called, hence a deadlock.

Yeah, looks about right. The culprit being rtnl_lock() in register_netdev().
Aren't these lock routines supposed to record the processor which obtained the
lock, and whinge if the same processor tries to obtain it again?

Anyway, here's the fix which should make the alternative arcnet encapsulations
work again...

--- linux/drivers/net/arcnet.c.hangs Sun Jun 7 11:52:19 1998
+++ linux/drivers/net/arcnet.c Sun Jun 7 12:44:40 1998
@@ -18,6 +18,13 @@

**********************

+ v3.02 (98/06/07)
+ - Use register_netdevice() instead of register_netdev() to create
+ new devices for RFC1051 and Ethernet encapsulation in arcnet_open.
+ Likewise for unregistering them later. This avoids the deadlock
+ encountered because the original routines call rtnl_lock() when
+ it's already locked. [dw]
+
v3.01 (98/04/17)
- Interrupt handler now also checks dev->[se]dev are non-NULL
to avoid crashes in interrupts during card init. [dw]
@@ -174,7 +181,7 @@
*/

static const char *version =
- "arcnet.c: v3.01 98/04/24 Avery Pennarun <apenwarr@bond.net> et al.\n";
+ "arcnet.c: v3.02 98/06/07 Avery Pennarun <apenwarr@bond.net> et al.\n";

#include <linux/module.h>
#include <linux/config.h>
@@ -462,7 +469,7 @@
}
sprintf(lp->edev->name,"%se",dev->name);
lp->edev->init=arcnetE_init;
- register_netdev(lp->edev);
+ register_netdevice(lp->edev);
#endif

#ifdef CONFIG_ARCNET_1051
@@ -472,7 +479,7 @@
lp->sdev->name=(char *)kmalloc(10,GFP_KERNEL);
sprintf(lp->sdev->name,"%ss",dev->name);
lp->sdev->init=arcnetS_init;
- register_netdev(lp->sdev);
+ register_netdevice(lp->sdev);
#endif

/* Enable TX if we need to */
@@ -548,7 +555,7 @@
#ifdef CONFIG_ARCNET_ETH
/* free the ethernet-encap protocol device */
lp->edev->priv=NULL;
- unregister_netdev(lp->edev);
+ unregister_netdevice(lp->edev);
kfree(lp->edev->name);
kfree(lp->edev);
lp->edev=NULL;
@@ -557,7 +564,7 @@
#ifdef CONFIG_ARCNET_1051
/* free the RFC1051-encap protocol device */
lp->sdev->priv=NULL;
- unregister_netdev(lp->sdev);
+ unregister_netdevice(lp->sdev);
kfree(lp->sdev->name);
kfree(lp->sdev);
lp->sdev=NULL;

---- ---- ----
David Woodhouse, Robinson College, CB3 9AN, England. (+44) 0976 658355
Dave@imladris.demon.co.uk http://www.imladris.demon.co.uk
finger pgp@dwmw2.robinson.cam.ac.uk for PGP key.

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