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spi: spi-sun6i: enable autosuspend feature 

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.

The commit also remove unnecessary call to pm_runtime_idle() used
to explicit put device to suspended state. Without pm_runtime_idle() PM
core will put device in the suspended state just after probe() returns.

Signed-off-by: Alexander Kochetkov <al.kochet@gmail.com>
Acked-by: Maxime Ripard <mripard@kernel.org>
Link: https://lore.kernel.org/r/20201019150343.2520-1-akochetkov@lintech.ru
Signed-off-by: Mark Brown <broonie@kernel.org>
This commit is contained in:
Alexander Kochetkov 2020-10-19 18:03:43 +03:00 committed by Mark Brown
parent 940f3bbf3d
commit ae0f18bef3
No known key found for this signature in database
GPG Key ID: 24D68B725D5487D0
1 changed files with 4 additions and 1 deletions
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5
drivers/spi/spi-sun6i.c
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@ -22,6 +22,8 @@
#include <linux/spi/spi.h>
#define SUN6I_AUTOSUSPEND_TIMEOUT 2000
#define SUN6I_FIFO_DEPTH 128
#define SUN8I_FIFO_DEPTH 64
@ -650,9 +652,10 @@ 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) {