From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH kernel 3.0-rc1] smc91c92_cs: set smc->base to NULL
 before iounmap
Date: Sun, 05 Jun 2011 14:38:34 -0700 (PDT)
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From: Ken Kawasaki <ken_kawasaki@spring.nifty.jp>
Date: Sun, 5 Jun 2011 08:20:16 +0900

> 
> smc91c92_cs:
>     set smc->base to NULL before iounmap
>     to avoid writing to smc->base in smc_interrupt.
> 
> Signed-off-by: Ken Kawasaki <ken_kawasaki@spring.nifty.jp>

The device should be completely made quiet and all interrupts
synchronized before unmapping chip registers.  Using NULL checks
is merely a workaround for the real problem, even though you take
great pains to assign NULL before the iounmap() call.

Perhaps putting the pcmcia_disable_device() call before the iounmap()
will be sufficient to fix this bug.  Or perhaps that, plus a call to
synchronize_irq() or similar.