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 00:16:06 +0200 Message-ID: <4C86B9A6.2050808@suse.cz> References: <4C72D310.4040004@suse.cz> <4C7B924D.6030703@panasas.com> <201009071712.54867.konrad@darnok.org> <4C86B1A4.8030308@oracle.com> <4C86B320.8090709@oracle.com> <1283897409.22844.7.camel@mulgrave.site> 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]:46626 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756295Ab0IGWQL (ORCPT ); Tue, 7 Sep 2010 18:16:11 -0400 Received: by fxm16 with SMTP id 16so349317fxm.19 for ; Tue, 07 Sep 2010 15:16:10 -0700 (PDT) In-Reply-To: <1283897409.22844.7.camel@mulgrave.site> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: James Bottomley Cc: Randy Dunlap , Konrad Rzeszutek Wilk , Boaz Harrosh , fischer@linux-buechse.de, linux-scsi@vger.kernel.org On 09/08/2010 12:10 AM, James Bottomley wrote: > On Tue, 2010-09-07 at 14:48 -0700, 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. > > Actually, the patch is this one: > > http://permalink.gmane.org/gmane.linux.scsi/5835 > > The complaint is that the driver spews warnings on a 64 bit compile, so > it's likely not 64 bit clean. As I wrote few minutes ago, there is only one which is in print. And I cannot find anybody fixing anything similar since 2.1. So can we enable it on 64-bit when we have two reports it works on 64-bit? (Is it still maintained? MAINTAINERS says so...) thanks, -- js suse labs