[PATCH 1/3] spi: stm32-qspi: fix pm_runtime usage_count counter

From: patrice.chotard
Date: Mon Apr 19 2021 - 08:16:18 EST


From: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>

pm_runtime usage_count counter is not well managed.
pm_runtime_put_autosuspend callback drops the usage_counter but this
one has never been increased. Add pm_runtime_get_sync callback to bump up
the usage counter. It is also needed to use pm_runtime_force_suspend and
pm_runtime_force_resume APIs to handle properly the clock.

Fixes: 9d282c17b023 ("spi: stm32-qspi: Add pm_runtime support")
Signed-off-by: Christophe Kerello <christophe.kerello@xxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/spi/spi-stm32-qspi.c | 18 ++++++++++++++----
1 file changed, 14 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-stm32-qspi.c b/drivers/spi/spi-stm32-qspi.c
index 947e6b9dc9f4..2786470a5201 100644
--- a/drivers/spi/spi-stm32-qspi.c
+++ b/drivers/spi/spi-stm32-qspi.c
@@ -727,21 +727,31 @@ static int __maybe_unused stm32_qspi_suspend(struct device *dev)
{
pinctrl_pm_select_sleep_state(dev);

- return 0;
+ return pm_runtime_force_suspend(dev);
}

static int __maybe_unused stm32_qspi_resume(struct device *dev)
{
struct stm32_qspi *qspi = dev_get_drvdata(dev);
+ int ret;
+
+ ret = pm_runtime_force_resume(dev);
+ if (ret < 0)
+ return ret;

pinctrl_pm_select_default_state(dev);
- clk_prepare_enable(qspi->clk);
+
+ ret = pm_runtime_get_sync(dev);
+ if (ret < 0) {
+ pm_runtime_put_noidle(dev);
+ return ret;
+ }

writel_relaxed(qspi->cr_reg, qspi->io_base + QSPI_CR);
writel_relaxed(qspi->dcr_reg, qspi->io_base + QSPI_DCR);

- pm_runtime_mark_last_busy(qspi->dev);
- pm_runtime_put_autosuspend(qspi->dev);
+ pm_runtime_mark_last_busy(dev);
+ pm_runtime_put_autosuspend(dev);

return 0;
}
--
2.17.1