From: Vinod Koul <vinod.koul@intel.com>
To: jiada_wang@mentor.com
Cc: dan.j.williams@intel.com, dmaengine@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel is stopped
Date: Mon, 27 Mar 2017 10:51:38 +0530 [thread overview]
Message-ID: <20170327052138.GG9308@localhost> (raw)
In-Reply-To: <1489731129-3166-2-git-send-email-jiada_wang@mentor.com>
On Thu, Mar 16, 2017 at 11:12:09PM -0700, jiada_wang@mentor.com wrote:
> From: Jiada Wang <jiada_wang@mentor.com>
>
> sdma_disable_channel() cannot ensure dma is stopped to access
> module's FIFOs. There is chance SDMA core is running and accessing
> BD when disable of corresponding channel, this may cause sometimes
> even after call of .sdma_disable_channel(), SDMA core still be
> running and accessing module's FIFOs.
>
> According to NXP R&D team a delay of one BD SDMA cost time (maximum
> is 1ms) should be added after disable of the channel bit, to ensure
> SDMA core has really been stopped after SDMA clients call
> .device_terminate_all.
>
> This patch introduces adds a new function sdma_disable_channel_with_delay()
> which simply adds 1ms delay after call sdma_disable_channel(),
> and set it as .device_terminate_all.
Applied after fixing the subsystem name.
--
~Vinod
prev parent reply other threads:[~2017-03-27 5:20 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-03-17 6:12 [PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel is stopped jiada_wang
2017-03-17 6:12 ` jiada_wang
2017-03-27 5:21 ` Vinod Koul [this message]
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