Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 10 Jun 2002 13:22:56 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 10 Jun 2002 13:22:55 -0400 Received: from mailout06.sul.t-online.com ([194.25.134.19]:16283 "EHLO mailout06.sul.t-online.com") by vger.kernel.org with ESMTP id convert rfc822-to-8bit; Mon, 10 Jun 2002 13:22:54 -0400 Content-Type: text/plain; charset=US-ASCII From: Oliver Neukum To: Tom Rini , Roland Dreier Subject: Re: PCI DMA to small buffers on cache-incoherent arch Date: Mon, 10 Jun 2002 19:22:26 +0200 X-Mailer: KMail [version 1.4] Cc: "David S. Miller" , linux-kernel@vger.kernel.org In-Reply-To: <52d6v19r9n.fsf@topspin.com> <523cvv9laj.fsf@topspin.com> <20020610170309.GC14252@opus.bloom.county> MIME-Version: 1.0 Content-Transfer-Encoding: 7BIT Message-Id: <200206101922.26985.oliver@neukum.name> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > > So is the consensus now that in general drivers should make sure any > > buffers passed to pci_map/unmap are aligned to SMP_CACHE_BYTES (and a > > multiple of SMP_CACHE_BYTES in size)? In other words if a driver uses > > an unaligned buffer it should be fixed unless we can prove (and > > document in a comment :) that it won't cause problems on an arch > > without cache coherency and with a writeback cache. > > And how about we don't call it SMP_CACHE_BYTES too? The processors > where this matters certainly aren't doing SMP... Definitely we should call it something different so we can limit it to architectures that need it. Regards Oliver - 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/