From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754154Ab0EHAJx (ORCPT ); Fri, 7 May 2010 20:09:53 -0400 Received: from mail-pz0-f204.google.com ([209.85.222.204]:49634 "EHLO mail-pz0-f204.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751075Ab0EHAJw (ORCPT ); Fri, 7 May 2010 20:09:52 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=c77QSE66tjhXOWGCj7x8qV/zkYVYC54XDwHa+pE3FFP5+X1/uUD8uqjav0mzn/WbdZ UbyM6yMHwLJ5HmSwgs7XBc2bf02LshgG3lmjGaGli/nY+R7DhPwnmBDOnFsNyJwJlT3c 9JnDW7GsrpzYWuVUNKlK8kQDWbPJYO7GnDUEE= MIME-Version: 1.0 In-Reply-To: <1272964935-10756-1-git-send-email-jassi.brar@samsung.com> References: <1272964935-10756-1-git-send-email-jassi.brar@samsung.com> Date: Fri, 7 May 2010 17:09:51 -0700 X-Google-Sender-Auth: d0722c43eb01002c Message-ID: Subject: Re: [PATCH] DMA ENGINE: Do not reset 'private' of channel From: Dan Williams To: Jassi Brar Cc: linux-kernel@vger.kernel.org, maciej.sosnowski@intel.com Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 4, 2010 at 2:22 AM, Jassi Brar wrote: > The member 'private' of 'struct dma_chan' is meant for passing > data between client and the controller driver. > > The DMA client driver may point it to platform specific stuff after > acquiring the channel. So, it is the responsiblity of the same code > to reset it, if it must. > > The DMA engine doesn't set it and hence, shouldn't reset it either. > > Signed-off-by: Jassi Brar > > This reseting of private by DMA Engine comes in the way of implementing > default channel settings during DMAC probe. That capability is useful > for not having the clients to always provide platform specific data, > like Rx/Tx FIFO addresses, which usually doesn't change across channel > requests. > Ok I like this explanation better than the changelog you have above because it clarifies that the driver is setting a default that the client can override at registration time, but when this is happening dmaengine should get out of the way. Applied. Thanks, Dan