From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 10 Jul 2008 18:38:45 +0100 (BST) Received: from [66.209.47.173] ([66.209.47.173]:21128 "EHLO mythtv.ewol.com") by ftp.linux-mips.org with ESMTP id S20022923AbYGJRin (ORCPT ); Thu, 10 Jul 2008 18:38:43 +0100 Received: from [127.0.0.1] (localhost.localdomain [127.0.0.1]) by mythtv.ewol.com (8.14.2/8.14.2) with ESMTP id m6AHcP9p027626; Thu, 10 Jul 2008 13:38:26 -0400 Message-ID: <48764911.50409@cortland.com> Date: Thu, 10 Jul 2008 13:38:25 -0400 From: Steve Brown Reply-To: sbrown@cortland.com User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: linux-mips@linux-mips.org CC: Michael Buesch Subject: Re: Correct way to set coherent_dma_mask on a non-pci device? References: <4873A676.8050906@cortland.com> <200807081955.47594.mb@bu3sch.de> In-Reply-To: <200807081955.47594.mb@bu3sch.de> Content-Type: multipart/mixed; boundary="------------040304090608000708050506" Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 19764 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: sbrown@cortland.com Precedence: bulk X-list: linux-mips This is a multi-part message in MIME format. --------------040304090608000708050506 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Michael Buesch wrote: > On Tuesday 08 July 2008 19:40:06 Steve Brown wrote: > >> There appears to be no function like pci_set_consistent_dma_mask to set >> the coherent mask for a non-pci device. >> >> What is the "proper" way to set it? >> >> The context for the question is a recent change to ssb_dma_set_mask() in >> drivers/ssb/main.c that removed the somewhat fragile, direct >> manipulation of dma_mask and coherent_dma_mask in favor of a call to >> dma_set_mask(). >> > > Note that SSB devices use the dma_*** API for doing DMA remappings. > So it uses dma_set_mask() for setting the mask. > > I can't find any dma_*** routine that references coherent_dma_mask. It looks like dma_set_mask() doesn't handle the case where the device doesn't support coherent dma (CONFIG_DMA_NONCOHERENT=y). Would this be the correct patch to handle that case? Steve --------------040304090608000708050506 Content-Type: text/plain; name="170-dma_set_mask.patch" Content-Transfer-Encoding: 7bit Content-Disposition: inline; filename="170-dma_set_mask.patch" diff --git a/include/asm-mips/dma-mapping.h b/include/asm-mips/dma-mapping.h index 230b3f1..8da4107 100644 --- a/include/asm-mips/dma-mapping.h +++ b/include/asm-mips/dma-mapping.h @@ -1,8 +1,9 @@ #ifndef _ASM_DMA_MAPPING_H #define _ASM_DMA_MAPPING_H -#include +#include #include +#include void *dma_alloc_noncoherent(struct device *dev, size_t size, dma_addr_t *dma_handle, gfp_t flag); @@ -48,7 +49,11 @@ extern int dma_supported(struct device *dev, u64 mask); static inline int dma_set_mask(struct device *dev, u64 mask) { - if(!dev->dma_mask || !dma_supported(dev, mask)) + if(!dma_supported(dev, mask)) + return -EIO; + if(!plat_device_is_coherent(dev)) + dev->dma_mask = &dev->coherent_dma_mask; + if(!dev->dma_mask) return -EIO; *dev->dma_mask = mask; --------------040304090608000708050506--