From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Ujfalusi Subject: Re: [PATCH 1/2] OMAP3: MCBSP: Suspend/resume failure fix Date: Fri, 20 Nov 2009 09:51:13 +0200 Message-ID: <200911200951.13181.peter.ujfalusi@nokia.com> References: <1258133987-20488-1-git-send-email-jwang@ti.com> <2ee9e08d0911191148x9da6112s960a283a7cffea7b@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <2ee9e08d0911191148x9da6112s960a283a7cffea7b@mail.gmail.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: alsa-devel-bounces@alsa-project.org Errors-To: alsa-devel-bounces@alsa-project.org To: "anuj.aggarwal@ti.com" Cc: "alsa-devel@alsa-project.org" , "linux-omap@vger.kernel.org" , "Wang, Jane" , "broonie@opensource.wolfsonmicro.com" List-Id: linux-omap@vger.kernel.org On Thursday 19 November 2009 21:48:26 ext Anuj Aggarwal wrote: > [Anuj] Yes, w/o audio, it goes into suspend neatly. > After going through the entire patch series "[PATCHv5 00/20] OMAP > ASoC changes in DMA utilization", which I missed earlier, I found that the > sysfs entry dma_op_mode can be toggled among element/frame/threshold, > by default which is element hence not allowing the mcbsp driver to go into > idle state. I changed that at run time and after that I am able to hit > the suspend > state while playing back audio (at least the log doesn't > show that the system is not able to hit suspend). > My question is: is sysfs the only way to choose threshold or can it be ma= de > as default? I could not see that happening in the code so thinking of the > possible reason of choosing not to do so. Because the user who wants to > hit suspend will not like to issue driver specific commands. Any specific > reason of not doing that by default? It is not selected as default on OMAP3, since it is a new feature, and we d= on't = want to change the behavior of the audio. If the reports are positive regar= ding = to the threshold mode, than we can make it as default on OMAP3, at least th= at is = the plan AFAIK. = In some cases the element mode is desirable over the threshold mode, and = probably there are additional modes can be implemented for other cases, hen= ce = the sysfs interface is really useful feature. Back than there were quite a bit of discussion here about the threshold mod= e: in = the original series the threshold mode was the default, but we decided to n= ot to = do that before others have the chance to test it. We have been using the = threshold mode without issues internally, so it should be really stable, bu= t it = is still a new mode, which can break other implementations. So please test the threshold mode in your HW, and report if it is working t= here = OK, if we have enough positive feedbacks, than we can make it as default. -- = P=E9ter