[PATCH] ibmtr_cs: fix hang on eject

[Paul Walmsley]

Sent this patch a few weeks ago to the addresses listed for Token Ring 
maintainers.  No response, and the linux-tr@ address bounced.  Resent 
here in case someone wants to pick it up.  Perhaps a MAINTAINERS edit 
might be in order also.


- Paul


Ejecting a PCMCIA IBM Token Ring card that has not had its dev->open() 
called will reliably trigger an uninitialized spinlock oops when spinlock 
debugging is enabled. The system then hangs, occasionally softlockup 
oopsing.  Apparently ibmtr.c:tok_interrupt() doesn't expect to be called 
before tok_open(), but tok_interrupt() gets called anyway when the card is 
ejected.  So, set an already-existing flag which causes tok_interrupt() to 
bail out early upon card ejection. Tested by inserting and removing the 
PCMCIA card several times.

Patch against 2.6.21-rc6.


Signed-off-by: Paul Walmsley <paul@xxxxxxxxxxx>

---
 dev/drivers/net/pcmcia/ibmtr_cs.c |   12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

Index: linux/dev/drivers/net/pcmcia/ibmtr_cs.c
===================================================================
--- linux.orig/dev/drivers/net/pcmcia/ibmtr_cs.c
+++ linux/dev/drivers/net/pcmcia/ibmtr_cs.c
@@ -189,16 +189,20 @@ static void ibmtr_detach(struct pcmcia_d
 {
     struct ibmtr_dev_t *info = link->priv;
     struct net_device *dev = info->dev;
+    struct tok_info *ti = netdev_priv(dev);

     DEBUG(0, "ibmtr_detach(0x%p)\n", link);
+
+    /*
+     * When the card removal interrupt hits tok_interrupt(),
+     * bail out early, so we don't crash the machine
+     */
+    ti->sram_phys |= 1;

     if (link->dev_node)
 	unregister_netdev(dev);

-    {
-	struct tok_info *ti = netdev_priv(dev);
-	del_timer_sync(&(ti->tr_timer));
-    }
+    del_timer_sync(&(ti->tr_timer));

     ibmtr_release(link);

-
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