Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759306Ab1FWLqZ (ORCPT ); Thu, 23 Jun 2011 07:46:25 -0400 Received: from h5.dl5rb.org.uk ([81.2.74.5]:43597 "EHLO duck.linux-mips.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1759217Ab1FWLqW (ORCPT ); Thu, 23 Jun 2011 07:46:22 -0400 Date: Thu, 23 Jun 2011 12:45:37 +0100 From: Ralf Baechle To: Greg Kroah-Hartman , devel@driverdev.osuosl.org, linux-kernel@vger.kernel.org, David Howells , linux-m32r@ml.linux-m32r.org, linux-m32r-ja@ml.linux-m32r.org, linux-am33-list@redhat.com, Paul Mundt , linux-sh@vger.kernel.org, Chris Metcalf , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , x86@kernel.org Cc: linux-arch@vger.kernel.org Subject: [PATCH] STAGING: Comedi: Build only on arches providing PAGE_KERNEL_NOCACHE Message-ID: <20110623114536.GA14011@linux-mips.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1870 Lines: 40 On architectures that don't define PAGE_KERNEL_NOCACHE, the Comedi driver turns into tragedy: CC [M] drivers/staging/comedi/drivers.o drivers/staging/comedi/drivers.c: In function ‘comedi_buf_alloc’: drivers/staging/comedi/drivers.c:505:41: error: ‘PAGE_KERNEL_NOCACHE’ undeclared (first use in this function) drivers/staging/comedi/drivers.c:505:41: note: each undeclared identifier is rep orted only once for each function it appears in make[3]: *** [drivers/staging/comedi/drivers.o] Error 1 Restrict the driver to only those architectures that define PAGE_KERNEL_NOCACHE. PAGE_KERNEL_NOCACHE is a kludge - some system architectures such as SGI IP27 are even uable to offer uncached operation - at least in the way an unwitting driver might assume. I haven't looked in details how the driver is using the area vmaped with PAGE_KERNEL_NOCACHE but maybe doing it XFS-style using cached memory and the flush_kernel_vmap_range / invalidate_kernel_vmap_range APIs in conjunction with the DMA API is a practical alternative. Signed-off-by: Ralf Baechle drivers/staging/comedi/Kconfig | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/staging/comedi/Kconfig b/drivers/staging/comedi/Kconfig index 1502d80..bccdc12 100644 --- a/drivers/staging/comedi/Kconfig +++ b/drivers/staging/comedi/Kconfig @@ -2,6 +2,7 @@ config COMEDI tristate "Data acquisition support (comedi)" default N depends on m + depends on BROKEN || FRV || M32R || MN10300 || SUPERH || TILE || X86 ---help--- Enable support a wide range of data acquisition devices for Linux. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/