Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is being used

From	Arnd Bergmann <arnd@arndb.de>
Newsgroups	linux.kernel
Subject	Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is being used
Date	2016-04-09 04:30 +0200
Message-ID	<rlQOS-6we-7@gated-at.bofh.it> (permalink)
References	<rl3bu-1Cm-47@gated-at.bofh.it> <rlcy6-kR-3@gated-at.bofh.it> <rlkvF-692-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On Thursday 07 April 2016, Al Stone wrote:
> >>>  config DEVPORT
> >>>       bool
> >>> -     depends on !M68K
> >>> +     depends on !M68K && !ARM64
> >>
> >> Why not fix the real bug here, it's odd that only these two arches need
> >> this disabled, don't you agree?
> 
> Agreed.  It does seem odd.  I'm not sure I understand which bug you're thinking
> is the real one, though -- that DEVPORT should be disabled in all places that
> don't have ISA or that arm64 needs to have /dev/port work properly?  Or perhaps
> I missed something else entirely...

We've had a similar problem recently with ISA drivers crashing when no PCI
host registers itself for the first 0x1000 I/O port addresses.

I think both the request_resource() function and /dev/ioport should be
changed to interface with the dynamic registration of I/O port ranges
so they only ever allow access on ports that are mapped into virtual memory.

	Arnd

Thread

[PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is being used Al Stone <ahs3@redhat.com> - 2016-04-06 23:30 +0200
  Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is  being used Greg Kroah-Hartman <gregkh@linuxfoundation.org> - 2016-04-07 02:20 +0200
    Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is  being used Geert Uytterhoeven <geert@linux-m68k.org> - 2016-04-07 09:30 +0200
      Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is  being used Al Stone <astone@redhat.com> - 2016-04-07 18:00 +0200
        Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is being used Arnd Bergmann <arnd@arndb.de> - 2016-04-09 04:30 +0200
        Re: [PATCH] arm64: CONFIG_DEVPORT should not be used when PCI is  being used Jon Masters <jcm@jonmasters.org> - 2016-04-12 07:20 +0200

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