From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: DMA example Date: Wed, 24 Feb 2010 12:35:56 -0800 Message-ID: <20100224203555.GT28173@atomide.com> References: <4B857F2F.7000201@balister.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:58061 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757959Ab0BXUfG (ORCPT ); Wed, 24 Feb 2010 15:35:06 -0500 Content-Disposition: inline In-Reply-To: <4B857F2F.7000201@balister.org> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Philip Balister Cc: "linux-omap@vger.kernel.org" * Philip Balister [100224 11:31]: > I am trying to setup a dma operation to copy memory from GPMC > address space into RAM. The only examples using the omap-dma api use > hardware triggers. > > When I start a transfer, I end up with a DMA transaction error when > I start the transfer. > > Does anyone have a good example of a software transfer? Currently, I > am tracing the omap dma api to see how things map into the registers > .... Enjoy the GPMC timings. I recommend attaching a logic analyzer there to verify the things are right for the key lines if you have chance. Hmm I thought the hardware triggers were optional in at least drivers/usb/musb/tusb6010_omap.c.. Maybe I don't remember correctly. Regards, Tony