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Date:   Wed, 27 Apr 2022 08:20:11 -0700
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Subject: Re: [RFC 1/1] drivers/dma/*: replace tasklets with workqueue
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To:     Vinod Koul <vkoul@kernel.org>,
        Allen Pais <apais@linux.microsoft.com>
Cc:     olivier.dautricourt@orolia.com, sr@denx.de, keescook@chromium.org,
        linux-hardening@vger.kernel.org, ludovic.desroches@microchip.com,
        tudor.ambarus@microchip.com, f.fainelli@gmail.com,
        rjui@broadcom.com, sbranden@broadcom.com,
        bcm-kernel-feedback-list@broadcom.com, nsaenz@kernel.org,
        paul@crapouillou.net, Eugeniy.Paltsev@synopsys.com,
        gustavo.pimentel@synopsys.com, vireshk@kernel.org,
        andriy.shevchenko@linux.intel.com, leoyang.li@nxp.com,
        zw@zh-kernel.org, wangzhou1@hisilicon.com, shawnguo@kernel.org,
        s.hauer@pengutronix.de, sean.wang@mediatek.com,
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        logang@deltatee.com, sanju.mehta@amd.com, daniel@zonque.org,
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        agross@kernel.org, bjorn.andersson@linaro.org,
        krzysztof.kozlowski@linaro.org, green.wan@sifive.com,
        orsonzhai@gmail.com, baolin.wang7@gmail.com, zhang.lyra@gmail.com,
        patrice.chotard@foss.st.com, linus.walleij@linaro.org,
        wens@csie.org, jernej.skrabec@gmail.com, samuel@sholland.org,
        dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org
References: <20220419211658.11403-1-apais@linux.microsoft.com>
 <20220419211658.11403-2-apais@linux.microsoft.com> <YmiuUy+PAjKEq6uE@matsya>
From:   Dave Jiang <dave.jiang@intel.com>
In-Reply-To: <YmiuUy+PAjKEq6uE@matsya>
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On 4/26/2022 7:45 PM, Vinod Koul wrote:
> On 19-04-22, 21:16, Allen Pais wrote:
>> The tasklet is an old API which will be deprecated, workqueue API
>> cab be used instead of them.
> What is the reason for tasklet removal, I am not sure old is a reason to
> remove an API...
>
>> This patch replaces the tasklet usage in drivers/dma/* with a
>> simple work.
> Dmaengines need very high throughput, one of the reasons in dmaengine
> API design to use tasklet was higher priority given to them. Will the
> workqueue allow that...?

Wouldn't the logical move be to convert threaded irq IF tasklets are 
being deprecated rather than using workqueue as replacement?

Also, wouldn't all the spin_lock_bh() calls need to be changed to 
spin_lock_irqsave() now? Probably not as simple as just replace tasklet 
with workqueue.