Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752128Ab1E2CWw (ORCPT ); Sat, 28 May 2011 22:22:52 -0400 Received: from smtp-out.google.com ([216.239.44.51]:32253 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751003Ab1E2CWv (ORCPT ); Sat, 28 May 2011 22:22:51 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=rM+fOMhMpdd8LKccbJle5AN8NAIqLgVGS84gxXXYucdNC9owYHnq9R8Mrp9aT8tzc7 X8qRVy1ARTHO2sY9KP+w== Date: Sat, 28 May 2011 19:22:44 -0700 (PDT) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Russell King - ARM Linux cc: Dmitry Eremin-Solenikov , Nicolas Pitre , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Eric Miao , Samuel Ortiz Subject: Re: IrDA driver fails on PXA255 In-Reply-To: <20110528234614.GV24876@n2100.arm.linux.org.uk> Message-ID: References: <20110528205701.GA1788@doriath.ww600.siemens.net> <20110528234614.GV24876@n2100.arm.linux.org.uk> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2304 Lines: 57 On Sun, 29 May 2011, Russell King - ARM Linux wrote: > > The driver is attempting to allocate DMA memory and you have > > CONFIG_ZONE_DMA disabled, which is the only reason you would get this > > warning. If the allocation did not fail as a result of a197b59ae6e8, the > > page allocator may return any memory in a higher zone that the driver may > > not be expecting. If you had never noticed a problem before, it may be > > possible that the driver doesn't actually have any zone restrictions and > > GFP_DMA can be removed, but this code is pretty old. Otherwise, it'll > > need to depend on ZONE_DMA in the Kconfig. > > > > Let's cc Nicolas and Russell as well. > > Ouch. We're probably going to have a pile of work to do to check that > the DMA masks on all our devices are correct for the unrestricted case > then. That's probably going to be a very _big_ patch. > There are probably a lot of drivers that are requesting DMA but don't explicitly require its support. ARM has always been one of the exceptions when it comes to enabling CONFIG_ZONE_DMA, most archs do by default (x86 _just_ made it configurable during this merge window), so this probably isn't the last report you'll get now that it fails the allocation and emits a warning. $ grep -r GFP_DMA drivers/* | wc -l 299 arm, pxa2xx: enable DMA support for pxa2xx IRDA interface The pxa2xx-ir driver allocates with GFP_DMA, so it must always have ZONE_DMA. Reported-by: Dmitry Eremin-Solenikov Signed-off-by: David Rientjes --- drivers/net/irda/Kconfig | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/drivers/net/irda/Kconfig b/drivers/net/irda/Kconfig --- a/drivers/net/irda/Kconfig +++ b/drivers/net/irda/Kconfig @@ -374,6 +374,7 @@ config VIA_FIR config PXA_FICP tristate "Intel PXA2xx Internal FICP" depends on ARCH_PXA && IRDA + select ZONE_DMA help Say Y or M here if you want to build support for the PXA2xx built-in IRDA interface which can support both SIR and FIR. -- 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/