[PATCH] spi: rockchip: enable autosuspend feature

[PATCH] spi: rockchip: 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-rockchip.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/spi/spi-rockchip.c b/drivers/spi/spi-rockchip.c
index 2cc6d9951b52..3e77b1a79bc8 100644
--- a/drivers/spi/spi-rockchip.c
+++ b/drivers/spi/spi-rockchip.c
@@ -157,6 +157,8 @@
 
 #define ROCKCHIP_SPI_MAX_CS_NUM			2
 
+#define ROCKCHIP_AUTOSUSPEND_TIMEOUT		2000
+
 struct rockchip_spi {
 	struct device *dev;
 
@@ -670,6 +672,8 @@ static int rockchip_spi_probe(struct platform_device *pdev)
 		goto err_disable_spiclk;
 	}
 
+	pm_runtime_set_autosuspend_delay(&pdev->dev, ROCKCHIP_AUTOSUSPEND_TIMEOUT);
+	pm_runtime_use_autosuspend(&pdev->dev);
 	pm_runtime_set_active(&pdev->dev);
 	pm_runtime_enable(&pdev->dev);
 
-- 
2.17.1

Re: [PATCH] spi: rockchip: enable autosuspend feature

[Mark Brown]

On Fri, 16 Oct 2020 11:50:14 +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: rockchip: enable autosuspend feature
      commit: 940f3bbf3dacd6e31e482a10e64c96e69b00dded

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