[PATCH] spi: spi-sun6i: enable autosuspend feature

[PATCH] spi: spi-sun6i: enable autosuspend feature

[Alexander Kochetkov]

If SPI is used for periodic polling any sensor, significant delays
sometimes appear. Switching on module clocks during resume lead to delays.
Enabling autosuspend mode causes the controller to not suspend between
SPI transfers and the delays disappear.

Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
---
 drivers/spi/spi-sun6i.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
index 38e5b8af7da6..4cc0280e934c 100644
--- a/drivers/spi/spi-sun6i.c
+++ b/drivers/spi/spi-sun6i.c
@@ -22,6 +22,8 @@
 
 #include <linux/spi/spi.h>
 
+#define SUN6I_AUTOSUSPEND_TIMEOUT	2000
+
 #define SUN6I_FIFO_DEPTH		128
 #define SUN8I_FIFO_DEPTH		64
 
@@ -639,9 +641,10 @@ static int sun6i_spi_probe(struct platform_device *pdev)
 		goto err_free_dma_rx;
 	}
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, SUN6I_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
-	pm_runtime_idle(&pdev->dev);
 
 	ret = devm_spi_register_master(&pdev->dev, master);
 	if (ret) {
-- 
2.17.1

Re: [PATCH] spi: spi-sun6i: enable autosuspend feature

[Maxime Ripard]

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Hi,

On Fri, Oct 16, 2020 at 11:38:26AM +0300, Alexander Kochetkov wrote:
> If SPI is used for periodic polling any sensor, significant delays
> sometimes appear. Switching on module clocks during resume lead to delays.
> Enabling autosuspend mode causes the controller to not suspend between
> SPI transfers and the delays disappear.
> 
> Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
> ---
>  drivers/spi/spi-sun6i.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/spi/spi-sun6i.c b/drivers/spi/spi-sun6i.c
> index 38e5b8af7da6..4cc0280e934c 100644
> --- a/drivers/spi/spi-sun6i.c
> +++ b/drivers/spi/spi-sun6i.c
> @@ -22,6 +22,8 @@
>  
>  #include <linux/spi/spi.h>
>  
> +#define SUN6I_AUTOSUSPEND_TIMEOUT	2000
> +
>  #define SUN6I_FIFO_DEPTH		128
>  #define SUN8I_FIFO_DEPTH		64
>  
> @@ -639,9 +641,10 @@ static int sun6i_spi_probe(struct platform_device *pdev)
>  		goto err_free_dma_rx;
>  	}
>  
> +	pm_runtime_set_autosuspend_delay(&pdev->dev, SUN6I_AUTOSUSPEND_TIMEOUT);
> +	pm_runtime_use_autosuspend(&pdev->dev);
>  	pm_runtime_set_active(&pdev->dev);
>  	pm_runtime_enable(&pdev->dev);
> -	pm_runtime_idle(&pdev->dev);

You should also mention why pm_runtime_idle isn't useful anymore in your
commit log.

Thanks!
Maxime

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Re: [PATCH] spi: spi-sun6i: enable autosuspend feature

[Mark Brown]

On Fri, 16 Oct 2020 11:38:26 +0300, Alexander Kochetkov wrote:
> If SPI is used for periodic polling any sensor, significant delays
> sometimes appear. Switching on module clocks during resume lead to delays.
> Enabling autosuspend mode causes the controller to not suspend between
> SPI transfers and the delays disappear.

Applied to

   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/spi.git for-next

Thanks!

[1/1] spi: spi-sun6i: enable autosuspend feature
      commit: ae0f18bef30d0e76dd62be46c59b24c75f175092

All being well this means that it will be integrated into the linux-next
tree (usually sometime in the next 24 hours) and sent to Linus during
the next merge window (or sooner if it is a bug fix), however if
problems are discovered then the patch may be dropped or reverted.

You may get further e-mails resulting from automated or manual testing
and review of the tree, please engage with people reporting problems and
send followup patches addressing any issues that are reported if needed.

If any updates are required or you are submitting further changes they
should be sent as incremental updates against current git, existing
patches will not be replaced.

Please add any relevant lists and maintainers to the CCs when replying
to this mail.

Thanks,
Mark