Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759105AbZCRR0a (ORCPT ); Wed, 18 Mar 2009 13:26:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758880AbZCRR0T (ORCPT ); Wed, 18 Mar 2009 13:26:19 -0400 Received: from wf-out-1314.google.com ([209.85.200.174]:12992 "EHLO wf-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758831AbZCRR0R convert rfc822-to-8bit (ORCPT ); Wed, 18 Mar 2009 13:26:17 -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 :content-transfer-encoding; b=ZrSv2qsjXBUbpsHC+56sSwYdxPvd9k2aBeHehz/CNiPasckXoefvaXVuoOnBvgcOeW etKkmBjMnEToEBwkxOMF/8kt37Eo4YBuijYQRAHP9qVmISrezOugwPM9KGi0V9d4AQVo Pn1l8WkDCUgvwAPOQ8SqHcHmvhlYvj52QSl4Y= MIME-Version: 1.0 In-Reply-To: <20090318.110154.76582864.nemoto@toshiba-tops.co.jp> References: <20090318.094935.238694196.nemoto@toshiba-tops.co.jp> <20090318.110154.76582864.nemoto@toshiba-tops.co.jp> Date: Wed, 18 Mar 2009 10:26:13 -0700 X-Google-Sender-Auth: 28eaa50d7ef021f8 Message-ID: Subject: Re: [PATCH 1/2] dmaengine: TXx9 Soc DMA Controller driver From: Dan Williams To: Atsushi Nemoto Cc: linux-mips@linux-mips.org, ralf@linux-mips.org, linux-kernel@vger.kernel.org, haavard.skinnemoen@atmel.com Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1559 Lines: 32 On Tue, Mar 17, 2009 at 7:01 PM, Atsushi Nemoto wrote: > On Tue, 17 Mar 2009 18:23:46 -0700, Dan Williams wrote: >> ?Or, just use some platform_data to identify the channel in the same >> manner as atmel-mci? > > Yes, I still want to control chan->chan_id. > > The atmel-mci does not select "channel". ?It just pick the first > usable channel of the dma_device specified by platform_data. ?I > suppose dw_dmac is symmetric (it can use any channel for any slave). You are right, it does not hardwire the channel, but it does hardwire the device, see at32_add_device_mci [1]. > But TXx9 SoC DMAC channels are hardwired to each peripheral devices. I think creating a dma_device instance per channel and specifying that device like atmel-mci is the more future-proof way to go. > And I want to call Channel-3 of DMAC-0 "dma0chan3" even if Channel-2 > was assigned to for public memcpy channel. The problem is you could pass in the chan_id to guarantee 'chan3', but there is no guarantee that you will get 'dma0', as the driver has no knowledge of what other dma devices may be in the system. [1] http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=blob;f=arch/avr32/mach-at32ap/at32ap700x.c;h=3fbfd1e32a9ee79af4f4545d95a9543b9070d189;hb=HEAD#l1327 -- 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/