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From: Stephen Warren <swarren@wwwdotorg.org>
To: Laxman Dewangan <ldewangan@nvidia.com>
Cc: vinod.koul@intel.com, dan.j.williams@intel.com,
	linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org
Subject: Re: [PATCH 2/2] dma: tegra: do not set transfer desc flag to DMA_CTRL_ACK in cyclic mode
Date: Fri, 22 Jun 2012 11:10:25 -0600	[thread overview]
Message-ID: <4FE4A701.1040303@wwwdotorg.org> (raw)
In-Reply-To: <1340365364-16276-2-git-send-email-ldewangan@nvidia.com>

On 06/22/2012 05:42 AM, Laxman Dewangan wrote:
> The sound dmaengine pcm driver uses the dma in cyclic mode and
> it does not ack the transfer descriptor  after transfer stops.
> This may lead to hold that desc in chip's dma driver and does
> not allow to reuse/free that descriptors. Hence not enabling
> flag DMA_CTRL_ACK when dma runs in cyclic mode.

> diff --git a/drivers/dma/tegra20-apb-dma.c b/drivers/dma/tegra20-apb-dma.c
> @@ -1093,7 +1093,7 @@ struct dma_async_tx_descriptor *tegra_dma_prep_dma_cyclic(
> -	dma_desc->txd.flags = DMA_CTRL_ACK;
> +	dma_desc->txd.flags = 0;

I honestly have no idea about this one. If the dmaengine maintainers
think it's semantically correct, I have no objections.

  reply	other threads:[~2012-06-22 17:10 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-06-22 11:42 [PATCH 1/2] dma: tegra: set DMA_CYCLIC capability Laxman Dewangan
2012-06-22 11:42 ` [PATCH 2/2] dma: tegra: do not set transfer desc flag to DMA_CTRL_ACK in cyclic mode Laxman Dewangan
2012-06-22 17:10   ` Stephen Warren [this message]
2012-06-22 17:09 ` [PATCH 1/2] dma: tegra: set DMA_CYCLIC capability Stephen Warren
2012-06-27 13:29 ` Vinod Koul
2012-06-27 13:42   ` Laxman Dewangan
2012-06-27 13:49     ` Vinod Koul

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