From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J.E.J. Bottomley" Subject: Re: [RFC][PATCH] move dma_mask into struct device Date: Sat, 16 Nov 2002 13:12:44 -0500 Sender: linux-scsi-owner@vger.kernel.org Message-ID: <200211161812.gAGICj604696@localhost.localdomain> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: (from root@localhost) by pogo.mtv1.steeleye.com (8.9.3/8.9.3) id KAA18080 for ; Sat, 16 Nov 2002 10:12:47 -0800 In-Reply-To: Message from Arnd Bergmann of "Sat, 16 Nov 2002 20:56:54 +0100." <200211162056.54008.arndb@de.ibm.com> List-Id: linux-scsi@vger.kernel.org To: Arnd Bergmann Cc: Linux Kernel , Linux Scsi arndb@de.ibm.com said: > You can easily keep out the pci stuff if you do something like this: No...look at what you've done. Now SCSI has to know about every bus type on every architecture; that's an extreme layering violation. architecture/bus types are generally only defined for the arch (PCI being the exception), so now the additions have to be #ifdef'd just so it will compile.. You've done this because you effectively have to pull a common but differently located structure element out of each of these bus specific devices. That implies to me that dma_mask should be in a common structure, which was the whole basis for the dmaable_device that I outlined previously. As I said, the only reason I haven't implemented dmaable_device is for expediency. James