From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Date: Thu, 24 Jul 2014 12:29:09 +0000 Subject: Re: [alsa-devel] DMA engine API issue Message-Id: <53D0FC15.6050601@metafoo.de> List-Id: References: <1406032431-3807-1-git-send-email-laurent.pinchart+renesas@ideasonboard.com> <87d2cwvmxa.wl%kuninori.morimoto.gx@gmail.com> <3361994.F0HgAeJkR9@avalon> <28702317.aD0C1Ga3DS@avalon> In-Reply-To: <28702317.aD0C1Ga3DS@avalon> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Laurent Pinchart , Kuninori Morimoto Cc: Linux-ALSA , linux-sh@vger.kernel.org, Vinod Koul , Magnus Damm , dmaengine@vger.kernel.org, Maxime Ripard , linux-arm-kernel@lists.infradead.org On 07/23/2014 01:07 PM, Laurent Pinchart wrote: [...] > Let's start by answering the background question and updating the DMA engine > API documentation once and for good : in which context are drivers allowed to > call the prep, tx_submit and issue_pending functions ? > I think the expectation is that these functions can be called in any context. Maybe what's missing is a way to tell the DMA engine driver to get ready and that it is going to be used very soon. This could be done from the sound devices open() callback. - Lars