Thread (5 messages) 5 messages, 2 authors, 2021-04-19
STALE1896d LANDED

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

From: <patrice.chotard@foss.st.com>
Date: 2021-04-19 12:16:18
Also in: linux-spi, lkml, stable
Subsystem: spi subsystem, the rest · Maintainers: Mark Brown, Linus Torvalds

From: Christophe Kerello <redacted>

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 <redacted>
Cc: stable@vger.kernel.org
---
 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


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