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Re: [PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel is stopped

From Vinod Koul <vinod.koul@intel.com>
Newsgroups linux.kernel
Subject Re: [PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel is stopped
Date 2017-03-27 07:30 +0200
Message-ID <tpvo6-2YI-7@gated-at.bofh.it> (permalink)
References <tlTp0-1N4-13@gated-at.bofh.it> <tlTp0-1N4-11@gated-at.bofh.it>
Organization linux.* mail to news gateway

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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

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[PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel is stopped <jiada_wang@mentor.com> - 2017-03-17 07:20 +0100
  Re: [PATCH v2] dma: imx-sdma: add 1ms delay to ensure SDMA channel  is stopped Vinod Koul <vinod.koul@intel.com> - 2017-03-27 07:30 +0200

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