Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932178AbaGBN3z (ORCPT ); Wed, 2 Jul 2014 09:29:55 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:37315 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753819AbaGBN3w (ORCPT ); Wed, 2 Jul 2014 09:29:52 -0400 From: Peter Ujfalusi To: , , , , Mark Brown , Liam Girdwood , , CC: , , Subject: [PATCH v2 4/5] ALSA: pcm_dmaengine: Correct support for 24bits physical sample widths Date: Wed, 2 Jul 2014 16:29:22 +0300 Message-ID: <1404307763-30557-5-git-send-email-peter.ujfalusi@ti.com> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1404307763-30557-1-git-send-email-peter.ujfalusi@ti.com> References: <1404307763-30557-1-git-send-email-peter.ujfalusi@ti.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case of _3LE/_3BE formats the samples are stored in 3 consecutive bytes without padding it to 4 bytes. This means that the DMA needs to be able to support 3 bytes word length in order to read/write the samples from memory correctly. Originally the code treated 24 bits physical length samples as they were 32 bits which leads to corruption when playing or recording audio. The hw.formats field has already been prepared to exclude formats not supported by the DMA engine in use, which means that only on platforms where 3 bytes is supported by the DMA will be able to use this format. Signed-off-by: Peter Ujfalusi --- sound/core/pcm_dmaengine.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/sound/core/pcm_dmaengine.c b/sound/core/pcm_dmaengine.c index d5611ec80381..6542c4083594 100644 --- a/sound/core/pcm_dmaengine.c +++ b/sound/core/pcm_dmaengine.c @@ -72,6 +72,8 @@ int snd_hwparams_to_dma_slave_config(const struct snd_pcm_substream *substream, buswidth = DMA_SLAVE_BUSWIDTH_1_BYTE; else if (bits == 16) buswidth = DMA_SLAVE_BUSWIDTH_2_BYTES; + else if (bits == 24) + buswidth = DMA_SLAVE_BUSWIDTH_3_BYTES; else if (bits <= 32) buswidth = DMA_SLAVE_BUSWIDTH_4_BYTES; else -- 2.0.0 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/