Subject: Re: next-20091007 - comedi driver build breaks on S390x

From: Martin Schwidefsky <[email-masked]>
Date: Wed, 7 Oct 2009 17:34:15 +0200

On Wed, 7 Oct 2009 06:07:44 -0700
Greg KH <[email-masked]> wrote:

> On Wed, Oct 07, 2009 at 04:24:58PM +0530, Kamalesh Babulal wrote:
> > Hi Greg,
> > 
> > 	next-20091007 randconfig build breaks on s390x with build error
> > 
> > drivers/staging/comedi/comedi_fops.c: In function 'comedi_mmap':
> > drivers/staging/comedi/comedi_fops.c:1453: error: 'PAGE_SHARED' undeclared (first use in this function)
> > drivers/staging/comedi/comedi_fops.c:1453: error: (Each undeclared identifier is reported only once
> > drivers/staging/comedi/comedi_fops.c:1453: error: for each function it appears in.)
> > make[3]: *** [drivers/staging/comedi/comedi_fops.o] Error 1
> 
> Odd.  What changed in the header files to cause this?

The problem has always been present, only now did randconfig find it.
The compile breaks because PAGE_SHARED is not defined for s390. The
equivalent define for s390 is PAGE_RW. The problem has not shown up so
far because all drivers who use the remap_pfn_range call with
PAGE_SHARED has dependencies not available on s390, e.g. CONFIG_PCI.

To fix this I see are two options: 1) add a PAGE_SHARED define to
arch/s390/include/asm/pgtable.h, 2) make comedi depend on !S390.

-- 
blue skies,
   Martin.

"Reality continues to ruin my life." - Calvin.