From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH 1/2] ASoC: dmaengine_pcm: Add support for packed transfers Date: Wed, 27 Apr 2016 16:14:24 +0200 Message-ID: <5720C940.5010809@metafoo.de> References: <1461763613-28714-1-git-send-email-hias@horus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1461763613-28714-1-git-send-email-hias@horus.com> Sender: linux-kernel-owner@vger.kernel.org To: Matthias Reichl , Jaroslav Kysela , Takashi Iwai , Liam Girdwood , Mark Brown , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Cc: kernel@martin.sperl.org List-Id: alsa-devel@alsa-project.org On 04/27/2016 03:26 PM, Matthias Reichl wrote: > dmaengine_pcm currently only supports setups where FIFO reads/writes > correspond to exactly one sample, eg 16-bit sample data is transferred > via 16-bit FIFO accesses, 32-bit data via 32-bit accesses. > > This patch adds support for setups with fixed width FIFOs where > multiple samples are packed into a larger word. > > For example setups with a 32-bit wide FIFO register that expect > 16-bit sample transfers to be done with the left+right sample data > packed into a 32-bit word. > > Support for packed transfers is controlled via the > SND_DMAENGINE_PCM_DAI_FLAG_PACK flag in snd_dmaengine_dai_dma_data.flags > > If this flag is set dmaengine_pcm doesn't put any restriction on the > supported formats and sets the DMA transfer width to undefined. > > This means control over the constraints is now transferred to the DAI > driver and it's responsible to provide proper configuration and > check for possible corner cases that aren't handled by the ALSA core. > > Signed-off-by: Matthias Reichl Looks good, thanks. Acked-by: Lars-Peter Clausen