Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262516AbVCIXQu (ORCPT ); Wed, 9 Mar 2005 18:16:50 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261251AbVCIXPf (ORCPT ); Wed, 9 Mar 2005 18:15:35 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:28809 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S262533AbVCIW7a (ORCPT ); Wed, 9 Mar 2005 17:59:30 -0500 Date: Wed, 9 Mar 2005 22:59:27 +0000 From: "'Christoph Hellwig'" To: "Bagalkote, Sreenivas" Cc: "'Christoph Hellwig'" , "'Arjan van de Ven'" , "'linux-kernel@vger.kernel.org'" , "'linux-scsi@vger.kernel.org'" , "'James Bottomley'" , "'Matt_Domsch@Dell.com'" , Andrew Morton Subject: Re: [ANNOUNCE][PATCH 2.6.11 2/3] megaraid_sas: Announcing new mod ule for LSI Logic's SAS based MegaRAID controllers Message-ID: <20050309225927.GA10646@infradead.org> Mail-Followup-To: 'Christoph Hellwig' , "Bagalkote, Sreenivas" , 'Arjan van de Ven' , "'linux-kernel@vger.kernel.org'" , "'linux-scsi@vger.kernel.org'" , 'James Bottomley' , "'Matt_Domsch@Dell.com'" , Andrew Morton References: <0E3FA95632D6D047BA649F95DAB60E570230CC22@exa-atlanta> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0E3FA95632D6D047BA649F95DAB60E570230CC22@exa-atlanta> User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 987 Lines: 22 On Wed, Mar 09, 2005 at 05:47:27PM -0500, Bagalkote, Sreenivas wrote: > > > >Even for kernels with a 64bit dma_addr_t you can get 32bit dma > >addresses > >only. As a start check whether the pci_set_dma_mask for the 64bit mask > >failed - in that case you can always use 32bit SGLs. > > > > Please help me understand: If dma_addr_t is 64 bit, I will get 64bit > addresses in scatterlist regardless the outcome of pci_set_dma_mask, > won't I? These addresses may have valid or null high addresses. My idea > was to have 32(64) bit SGLs for 32(64) bit dma_addr_t. if pci_set_dma_mask for the 64bit mask fails the upper 32bit bit of dma_addr_t will guaranteed to be zero, so you don't need to take them into account for your hardware SGL. - 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/