From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jiri Slaby Subject: Re: Why is AHA152X_CS !64BIT? Date: Wed, 08 Sep 2010 00:10:40 +0200 Message-ID: <4C86B860.1070105@suse.cz> References: <4C72D310.4040004@suse.cz> <4C7B924D.6030703@panasas.com> <201009071712.54867.konrad@darnok.org> <4C86B1A4.8030308@oracle.com> <4C86B320.8090709@oracle.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mail-fx0-f46.google.com ([209.85.161.46]:63486 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753578Ab0IGWKq (ORCPT ); Tue, 7 Sep 2010 18:10:46 -0400 Received: by fxm16 with SMTP id 16so346828fxm.19 for ; Tue, 07 Sep 2010 15:10:44 -0700 (PDT) In-Reply-To: <4C86B320.8090709@oracle.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Randy Dunlap Cc: Konrad Rzeszutek Wilk , Boaz Harrosh , fischer@linux-buechse.de, linux-scsi@vger.kernel.org, Andi Kleen On 09/07/2010 11:48 PM, Randy Dunlap wrote: > On 09/07/10 14:41, Randy Dunlap wrote: >> On 09/07/10 14:12, Konrad Rzeszutek Wilk wrote: >>> On Monday 30 August 2010 07:13:17 Boaz Harrosh wrote: >>>> On 08/23/2010 10:59 PM, Jiri Slaby wrote: >>>>> Hi, >>>>> >>>>> I see that the aha152x driver for pcmcia is marked as unsupported on >>>>> 64bit. But I also see a patch [1] which removes the restriction based on >>>>> user's testing in bugzilla [2]. >>>>> >>>>> Is there a reason why it would have to be marked as !64BIT? I'm asking >>>>> because there is an opensuse user with this card who updated to 64-bit >>>>> distro and lost this driver thereafter. >>>>> >>>>> [1] http://kerneltrap.org/mailarchive/linux-scsi/2010/3/6/6832393 >>>>> [2] https://bugzilla.kernel.org/show_bug.cgi?id=14333 >>>>> >>>>> thanks, >>>> >>>> If memory serves correctly, it might be that you need more then 4 Gbyte >>>> of memory installed to exercise the bug, something about IO bouncing >>>> addresses > 4G. >>> >>> If the machine is using SWIOTLB, then the bounce buffer would be activated. By >>> default if your machine has more than 4GB compiled under x86_64 the SWIOTLB >>> is turned on - but if you have an Intel/AMD IOMMU it gets turned off. Which >>> is OK as the Intel/AMD IOMMUs would handle the 4GB restricted devices. So as >>> long as the driver has pci_dma_mask_set. >>> >>> Looking at the git gui blame tool history, the reason that was added was >>> for 'allow drivers to be built non-modular'. >> >> 023ae619 (Robert P. J. Day 2007-03-26 16:06:45 -0400 14) depends on !64BIT >> >> That commit just removed the "depends on m" part: >> >> - depends on m && !64BIT >> + depends on !64BIT >> >> >>> So, does this driver build if you make it non-modular? >> >> It shouldn't since it still depends on !64BIT. >> >> I expect someone thought or had evidence that the driver was not 64-bit clean. >> >> Is the bitkeeper kernel repo still visible somewhere? >> Looks like we would need to look at it for patch history that far back. >> > > http://linux.bkbits.net:8080/linux-2.6/?PAGE=cset&REV=3fe0bc41KO89ooP68UcrHEMVVAfDnw > > but it doesn't quite make sense to me. Sure, no ISA on x86_64, but that does not > mean no PCMCIA on x86_64. Hmm, the changelog says: The warning I saw was actually for the PCMCIA aha152x driver. which I think are compiler warnings. But I see only one emitted by the compiler and it is in a debug print. thanks, -- js suse labs