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Date: Sun, 12 Aug 2007 10:51:17 -0700 (PDT)
From: Don Lewis <truckman@FreeBSD.org>
To: bruce@cran.org.uk
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Cc: current@FreeBSD.org
Subject: Re: RE: Reboot on "shutdown -r" hangs after final "uptime ..."
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On 12 Aug, bruce@cran.org.uk wrote:
> On Sat, Aug 11, 2007 at 09:42:55PM -0700, Don Lewis wrote:

> Thanks for your help. The revised patch doesn't change the behaviour;

It was a shot in the dark ...

> in
> ehci_pci_givecontroller, eec has the value 0x1000001 and the
> pci_read_config returns 0xC0002000.   Disabling the
> SMI bit doesn't help either,

Whoops, bit 13 is set in this register.  In my test code, I told you to
use the mask ~0x200, but the mask should have been ~0x2000.

> but something I have noticed it that
> (both with and without the SMI disabling code) I get an 'f' printed on
> the console occasionally, which is probably from the printf I put in, 
> "finished in ehci_pci_givecontroller":
> 
> // code to disable SMI bit...
> DPRINTF(("pci_write_config in ehci_pci_givecontroller\n"));
> pci_write_config(...)
> // end for loop
> DPRINT(("finished in ehci_pci_givecontroller\n"));
> // end of ehci_pci_givecontroller function
> 
> which suggests that something is
> causing the system to hang after the pci_write_config has finished.

The logical thing would be the SMI triggered by the pci_write_config().
There might be some uncertainty about the timing of the interrupt, which
would account for the uncertainty in the appearance of the 'f'.