From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
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>
Subject: Re: [PATCH v3 2/3] spi: s3c64xx: add sleep during transfer
Date: Fri, 5 May 2023 11:09:29 +0200 [thread overview]
Message-ID: <862cc092-d561-7e65-e8d4-a1c2d56a52ab@linaro.org> (raw)
In-Reply-To: <20230502062813.112434-3-jaewon02.kim@samsung.com>
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
WARNING: multiple messages have this Message-ID (diff)
From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
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>
Subject: Re: [PATCH v3 2/3] spi: s3c64xx: add sleep during transfer
Date: Fri, 5 May 2023 11:09:29 +0200 [thread overview]
Message-ID: <862cc092-d561-7e65-e8d4-a1c2d56a52ab@linaro.org> (raw)
In-Reply-To: <20230502062813.112434-3-jaewon02.kim@samsung.com>
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
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next prev parent reply other threads:[~2023-05-05 9:09 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <CGME20230502065025epcas2p16f5a02e6990d6f2b2257f001979ebcf9@epcas2p1.samsung.com>
2023-05-02 6:28 ` [PATCH v3 0/3] Improve polling mode of s3c64xx driver Jaewon Kim
2023-05-02 6:28 ` Jaewon Kim
[not found] ` <CGME20230502065025epcas2p4143c8ff3d44b7676ea8667c14618f2cd@epcas2p4.samsung.com>
2023-05-02 6:28 ` [PATCH v3 1/3] spi: s3c64xx: change polling mode to optional Jaewon Kim
2023-05-02 6:28 ` Jaewon Kim
2023-05-05 9:09 ` Krzysztof Kozlowski
2023-05-05 9:09 ` Krzysztof Kozlowski
[not found] ` <CGME20230502065025epcas2p11549db7400e6707c61bbb1cff1b22252@epcas2p1.samsung.com>
2023-05-02 6:28 ` [PATCH v3 2/3] spi: s3c64xx: add sleep during transfer Jaewon Kim
2023-05-02 6:28 ` Jaewon Kim
2023-05-05 9:09 ` Krzysztof Kozlowski [this message]
2023-05-05 9:09 ` Krzysztof Kozlowski
[not found] ` <CGME20230502065025epcas2p34507ffad60b32e091ff0efeced9bc12f@epcas2p3.samsung.com>
2023-05-02 6:28 ` [PATCH v3 3/3] spi: s3c64xx: support interrupt based pio mode Jaewon Kim
2023-05-02 6:28 ` Jaewon Kim
2023-05-05 9:47 ` Krzysztof Kozlowski
2023-05-05 9:47 ` Krzysztof Kozlowski
2023-05-08 1:42 ` Jaewon Kim
2023-05-08 1:42 ` Jaewon Kim
2023-05-09 13:03 ` Marek Szyprowski
2023-05-10 4:05 ` Jaewon Kim
2023-05-10 6:54 ` Marek Szyprowski
2023-05-08 13:27 ` [PATCH v3 0/3] Improve polling mode of s3c64xx driver Mark Brown
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