Re: port-amd64/48142: i8254 timer stop working during boot - system lockup during boot

[David Laight <david%l8s.co.uk@localhost>]

The following reply was made to PR port-amd64/48142; it has been noted by GNATS.

From: David Laight <david%l8s.co.uk@localhost>
To: gnats-bugs%NetBSD.org@localhost
Cc: 
Subject: Re: port-amd64/48142: i8254 timer stop working during boot - system 
lockup during boot
Date: Thu, 22 Aug 2013 08:30:04 +0100

 On Wed, Aug 21, 2013 at 01:00:01PM +0000, 
Wolfgang.Stukenbrock%nagler-company.com@localhost wrote:
 > >Number:         48142
 > >Category:       port-amd64
 > >Synopsis:       i8254 timer stop working during boot - system lockup during 
 > >boot
 ...
 >      The problem is triggered by the finsio driver on port 0x4e,
 >       but I'm not shure if it is the fault of this driver or
 >      if the timer registers are visible on other ports than 0x40 and
 >       0x43 on this board too.
 
 Why are you enabling the finsio driver?
 Enabling 'random' ISA drivers will always cause grief, the 'grope'
 code can easily destroy other hardware.
 The finsio grope is very nasty - it does io-writes - so you really shouldn't
 enable it unless you really need it and expect the grope to succeed.
 Restoring the origanl value might help.
 
 I'd certainly add some debug to read the 8254 timer ports during the
 finsio grop code - so work out exactly when they are clobbered.
 IIRC reads from the timer registers are always ok.
 Might be worth doing byte reads of ports 0x40 through 0x4f just to
 see it the timer registers are aliased.
 
        David
 
 -- 
 David Laight: david%l8s.co.uk@localhost