This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
Home Products Support Community News


Re: [Xen-devel] Xen Kernel (3.0.2) breaks b44 module

To: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Subject: Re: [Xen-devel] Xen Kernel (3.0.2) breaks b44 module
From: Keir Fraser <Keir.Fraser@xxxxxxxxxxxx>
Date: Fri, 12 May 2006 10:03:55 +0100
Cc: xen@xxxxxxxxxx, xen-devel@xxxxxxxxxxxxxxxxxxx
Delivery-date: Fri, 12 May 2006 02:04:18 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxx
In-reply-to: <44646A15.76E4.0078.0@xxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/cgi-bin/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
References: <00a801c67599$bfc2ab50$fe02420a@BDR529> <44646A15.76E4.0078.0@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx

On 12 May 2006, at 09:57, Jan Beulich wrote:

This ought to be attributed to the fact that B44 supports only 30-bit DMA addresses (and does special checking), but XenLinux doesn't have a distinct DMA zone restricted to 24-bit addresses, and both dma_alloc_coherent() and swiotlb are restricting physical addresses to 31 bits only (at least the former could certainly look at the device's DMA mask and
use that value rather than hard-coding 31).

If dma_alloc_coherent isn't doing that then it should be patched to do so. Even though it won't help right now (since Xen will reject any requests more restricted than 31 bits) it will be needed when Xen is fixed to support basket-case hardware.

 -- Keir

Xen-devel mailing list