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Subject: Re: [PATCH 00/46] Use dmaenginem_async_device_register to simplify
 code
To:     Huang Shijie <sjhuang@iluvatar.ai>, vkoul@kernel.org
Cc:     dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org,
        dave.jiang@intel.com, radhey.shyam.pandey@xilinx.com,
        appana.durga.rao@xilinx.com, jmkrzyszt@gmail.com,
        gomonovych@gmail.com, peter.ujfalusi@ti.com, keescook@chromium.org,
        horms+renesas@verge.net.au, geert+renesas@glider.be,
        shawnguo@kernel.org, baoyou.xie@linaro.org,
        michal.simek@xilinx.com, baohua@kernel.org,
        ludovic.desroches@microchip.com, linus.walleij@linaro.org,
        david.brown@linaro.org
References: <20180803072016.21544-1-sjhuang@iluvatar.ai>
From:   Lars-Peter Clausen <lars@metafoo.de>
Message-ID: <2ca11b6e-3afc-d55f-6df7-88a8a4a88873@metafoo.de>
Date:   Fri, 3 Aug 2018 09:51:43 +0200
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On 08/03/2018 09:19 AM, Huang Shijie wrote:
> All the patches are using dmaenginem_async_device_register to simplify code
> except the last one:
>   dmaengine: add COMPILE_TEST for the drivers
> 
> I use the last one to do the compiler test.  
> There are still 20 drivers which do not use the dmaenginem_async_device_register.
> Let me take a rest, if this patch set is accepted, I will do the rest.

Lots of race conditions in this series. The DMA device needs to be removed
before any of the resources it uses are disabled/released.

As a rule of thumb you can only convert something to a managed
allocation/reregistration if it is the last action in remove.