Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752921Ab0HZKCH (ORCPT ); Thu, 26 Aug 2010 06:02:07 -0400 Received: from sh.osrg.net ([192.16.179.4]:39689 "EHLO sh.osrg.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752045Ab0HZKCE (ORCPT ); Thu, 26 Aug 2010 06:02:04 -0400 Date: Thu, 26 Aug 2010 19:00:24 +0900 To: u.kleine-koenig@pengutronix.de Cc: fujita.tomonori@lab.ntt.co.jp, g.liakhovetski@gmx.de, mitov@issp.bas.bg, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, akpm@linux-foundation.org, linux-arm-kernel@lists.infradead.org, linux-sh@vger.kernel.org, philippe.retornaz@epfl.ch, gregkh@suse.de, jkrzyszt@tis.icnet.pl Subject: Re: [RFC][PATCH] add dma_reserve_coherent_memory()/dma_free_reserved_memory() API From: FUJITA Tomonori In-Reply-To: <20100826095311.GA13051@pengutronix.de> References: <20100826182915S.fujita.tomonori@lab.ntt.co.jp> <20100826095311.GA13051@pengutronix.de> Mime-Version: 1.0 Content-Type: Text/Plain; charset=iso-2022-jp-2 Content-Transfer-Encoding: 7bit Message-Id: <20100826185938A.fujita.tomonori@lab.ntt.co.jp> X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-3.0 (sh.osrg.net [192.16.179.4]); Thu, 26 Aug 2010 19:00:26 +0900 (JST) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1647 Lines: 29 On Thu, 26 Aug 2010 11:53:11 +0200 Uwe Kleine-K$(D+S(Bnig wrote: > > > We have currently a number of boards broken in the mainline. They must be > > > fixed for 2.6.36. I don't think the mentioned API will do this for us. So, > > > as I suggested earlier, we need either this or my patch series > > > > > > http://thread.gmane.org/gmane.linux.ports.sh.devel/8595 > > > > > > for 2.6.36. > > > > Why can't you revert a commit that causes the regression? > > > > The related DMA API wasn't changed in 2.6.36-rc1. The DMA API is not > > responsible for the regression. And the patchset even exnteds the > > definition of the DMA API (dma_declare_coherent_memory). Such change > > shouldn't applied after rc1. I think that DMA-API.txt says that > > dma_declare_coherent_memory() handles coherent memory for a particular > > device. It's not for the API that reserves coherent memory that can be > > used for any device for a single device. > The patch that made the problem obvious for ARM is > 309caa9cc6ff39d261264ec4ff10e29489afc8f8 aka v2.6.36-rc1~591^2~2^4~12. > So this went in before v2.6.36-rc1. One of the "architectures which > similar restrictions" is x86 BTW. > > And no, we won't revert 309caa9cc6ff39d261264ec4ff10e29489afc8f8 as it > addresses a hardware restriction. How these drivers were able to work without hitting the hardware restriction? -- 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/