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Message-ID: <862cc092-d561-7e65-e8d4-a1c2d56a52ab@linaro.org>
Date:   Fri, 5 May 2023 11:09:29 +0200
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Subject: Re: [PATCH v3 2/3] spi: s3c64xx: add sleep during transfer
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To:     Jaewon Kim <jaewon02.kim@samsung.com>,
        Andi Shyti <andi@etezian.org>, Mark Brown <broonie@kernel.org>,
        Alim Akhtar <alim.akhtar@samsung.com>
Cc:     linux-spi@vger.kernel.org, linux-samsung-soc@vger.kernel.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        Chanho Park <chanho61.park@samsung.com>
References: <20230502062813.112434-1-jaewon02.kim@samsung.com>
 <CGME20230502065025epcas2p11549db7400e6707c61bbb1cff1b22252@epcas2p1.samsung.com>
 <20230502062813.112434-3-jaewon02.kim@samsung.com>
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230502062813.112434-3-jaewon02.kim@samsung.com>
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On 02/05/2023 08:28, Jaewon Kim wrote:
> In polling mode, the status register is continuously read to check data
> transfer completion. It can cause excessive CPU usage.
> To reduce this, we can calculate the transfer time and put the sleep during
> transfer.
> 
> When test on ExynosAuto9 SADK board, throughput remained the same, but
> 100% CPU utilization decreased to 40%.
> 
> Signed-off-by: Jaewon Kim <jaewon02.kim@samsung.com>
> ---

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

Best regards,
Krzysztof