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Date:   Thu, 6 Apr 2023 20:49:50 +0100 (BST)
From:   "Maciej W. Rozycki" <macro@orcam.me.uk>
To:     Randy Dunlap <rdunlap@infradead.org>
cc:     linux-kernel@vger.kernel.org,
        Sudip Mukherjee <sudipm.mukherjee@gmail.com>,
        "David S. Miller" <davem@davemloft.net>,
        sparclinux@vger.kernel.org, Sam Ravnborg <sam@ravnborg.org>,
        linux-parport@lists.infradead.org
Subject: Re: [PATCH] parport_pc: don't allow driver for SPARC32
In-Reply-To: <20230406160548.25721-1-rdunlap@infradead.org>
Message-ID: <alpine.DEB.2.21.2304062039260.44308@angie.orcam.me.uk>
References: <20230406160548.25721-1-rdunlap@infradead.org>
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On Thu, 6 Apr 2023, Randy Dunlap wrote:

> arch/sparc/kernel/ebus.o is only built for SPARC64.
> ns87303_lock is only built for SPARC64.
> arch/sparc/include/asm/parport.h says that it is for sparc64.
> Various documentation on the internet says that ebus is for UltraSPARC
> systems (64-bit).
> 
> Therefore don't allow PARPORT_PC to be built for SPARC32.

 This looks completely wrong to me, any ordinary PCI parallel port card 
ought just to work as long as you have PCI (S390 is special I'm told).  
What needs to be done is AFAICT just making `parport_pc_find_nonpci_ports' 
in arch/sparc/include/asm/parport.h SPARC64-specific, i.e.:

static int parport_pc_find_nonpci_ports(int autoirq, int autodma)
{
	return (IS_ENABLED(CONFIG_SPARC64) &&
		platform_driver_register(&ecpp_driver));
}

or suchlike and let the optimiser get rid of all the unwanted unsupported 
stuff.

  Maciej