From mboxrd@z Thu Jan 1 00:00:00 1970 From: Takashi Iwai Subject: Re: [PATCH 2/4] ALSA: hda: Make sure DMA is started by reading back the RUN bit Date: Tue, 15 May 2018 09:36:19 +0200 Message-ID: References: <1526366456-20470-1-git-send-email-sriramx.periyasamy@intel.com> <1526366456-20470-3-git-send-email-sriramx.periyasamy@intel.com> Mime-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mx2.suse.de (mx2.suse.de [195.135.220.15]) by alsa0.perex.cz (Postfix) with ESMTP id 31984266F0F for ; Tue, 15 May 2018 09:36:20 +0200 (CEST) In-Reply-To: <1526366456-20470-3-git-send-email-sriramx.periyasamy@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Sriram Periyasamy Cc: Liam Girdwood , Patches Audio , ALSA ML , Mark Brown , Pardha Saradhi K List-Id: alsa-devel@alsa-project.org On Tue, 15 May 2018 08:40:54 +0200, Sriram Periyasamy wrote: > > From: Pardha Saradhi K > > As per HW recommendation, after setting the RUN bit, > software must read a 1 from the RUN bit, before modifying > related control registers/re-starting the DMA engine. Rather FIFO is checked in snd_hdac_stream_sync(), so I guess it already suffices. But we can add this sanity check there, too, if it really matters. thanks, Takashi