[PACTH v2] i2c: imx-lpi2c: mark I2C adapter when hardware is powered down

[Carlos Song (OSS)]

From: Carlos Song <carlos.song at nxp.com>

Mark the I2C adapter as suspended during system suspend to block further
transfers, and resume it on system resume. This prevents potential hangs
when the hardware is powered down but clients still attempt I2C transfers.

Fixes: 1ee867e465c1 ("i2c: imx-lpi2c: add target mode support")
Cc: stable at vger.kernel.org
Signed-off-by: Carlos Song <carlos.song at nxp.com>
---
Change for v2:
  - Call i2c_mark_adapter_suspended() before pm_runtime_force_suspend()
    to prevent potential deadlock if a transfer is active during suspend.
  - Roll back with i2c_mark_adapter_resumed() if pm_runtime_force_suspend()
    fails.
---
 drivers/i2c/busses/i2c-imx-lpi2c.c | 15 ++++++++++++++-
 1 file changed, 14 insertions(+), 1 deletion(-)

diff --git a/drivers/i2c/busses/i2c-imx-lpi2c.c b/drivers/i2c/busses/i2c-imx-lpi2c.c
index a01c23696481..01ee38131ef2 100644
--- a/drivers/i2c/busses/i2c-imx-lpi2c.c
+++ b/drivers/i2c/busses/i2c-imx-lpi2c.c
@@ -1635,7 +1635,18 @@ static int __maybe_unused lpi2c_runtime_resume(struct device *dev)
 
 static int __maybe_unused lpi2c_suspend_noirq(struct device *dev)
 {
-	return pm_runtime_force_suspend(dev);
+	struct lpi2c_imx_struct *lpi2c_imx = dev_get_drvdata(dev);
+	int ret;
+
+	i2c_mark_adapter_suspended(&lpi2c_imx->adapter);
+
+	ret = pm_runtime_force_suspend(dev);
+	if (ret) {
+		i2c_mark_adapter_resumed(&lpi2c_imx->adapter);
+		return ret;
+	}
+
+	return 0;
 }
 
 static int __maybe_unused lpi2c_resume_noirq(struct device *dev)
@@ -1655,6 +1666,8 @@ static int __maybe_unused lpi2c_resume_noirq(struct device *dev)
 	if (lpi2c_imx->target)
 		lpi2c_imx_target_init(lpi2c_imx);
 
+	i2c_mark_adapter_resumed(&lpi2c_imx->adapter);
+
 	return 0;
 }
 
-- 
2.43.0