From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tony Lindgren Subject: Re: [OMAP3] ALSA driver 'suspend/resume' handlers Date: Wed, 7 Oct 2009 14:42:55 -0700 Message-ID: <20091007214254.GA29320@atomide.com> References: <2183bec20909221938mf436e87y7620613e160ae6e2@mail.gmail.com> <2183bec20909222202u7ada82e1ycb1de4702822e171@mail.gmail.com> <20090924094608.542909b7.jhnikula@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from mho-01-ewr.mailhop.org ([204.13.248.71]:53325 "EHLO mho-01-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753400AbZJGVnk (ORCPT ); Wed, 7 Oct 2009 17:43:40 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: "Pandita, Vikram" Cc: "Shilimkar, Santosh" , Jarkko Nikula , hari n , "linux-omap@vger.kernel.org" * Pandita, Vikram [090924 05:59]: > > > >-----Original Message----- > >From: Shilimkar, Santosh > >Sent: Thursday, September 24, 2009 2:24 AM > >To: Jarkko Nikula; hari n > >Cc: Pandita, Vikram; linux-omap@vger.kernel.org > >Subject: RE: [OMAP3] ALSA driver 'suspend/resume' handlers > > > >Hari/Jarkko, > >> -----Original Message----- > >> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap- > >> owner@vger.kernel.org] On Behalf Of Jarkko Nikula > >> Sent: Thursday, September 24, 2009 12:16 PM > >> To: hari n > >> Cc: Pandita, Vikram; linux-omap@vger.kernel.org > >> Subject: Re: [OMAP3] ALSA driver 'suspend/resume' handlers > >> > >> On Wed, 23 Sep 2009 00:02:01 -0500 > >> hari n wrote: > >> > >omap_stop_dma() should be issued when we really want to stop the DMA transfer and issuing this with > >an outstanding transfer is a BUG in ALSA driver. > > > >Having said that, there is also bug in the DMA driver which doesn't disable the channel in linking > >cases. Since we use always hardware synchronized method, hardware will take care of draining the > >buffer so no loss of data. > > > >So option B should be ok and USB case also would work as mentioned above. > > USB is not a valid use case to discuss here. > Mentor OTG controller has its internal DMA and so does EHCI/OHCI host controller. > USB on OMAP3 _does_not_ use system DMA. At least tusb6010 connected to 2420 on n800 and n810 uses the system DMA. Tony