[PATCH 7/8] pwm: tiehrpwm: Enable runtime PM before registering PWM chip

[Lee Jones]

ehrpwm_pwm_probe() calls pwmchip_add() before setting driver data and
enabling runtime PM.  Because pwmchip_add() immediately exposes the PWM
channels to consumers, a consumer can invoke ehrpwm_pwm_apply() before
pm_runtime_enable() runs, causing registers to be accessed while the
device remains runtime-suspended.

Set driver data and enable runtime PM before calling pwmchip_add(), and
disable runtime PM on the error path.

Fixes: 19891b20e7c2 ("pwm: pwm-tiehrpwm: PWM driver support for EHRPWM")
Closes: https://sashiko.dev/#/bug/linux-28b36a80-e4a9-4bb6-97bc-7ca02895570a
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Lee Jones <lee@xxxxxxxxxx>
---
 drivers/pwm/pwm-tiehrpwm.c | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/drivers/pwm/pwm-tiehrpwm.c b/drivers/pwm/pwm-tiehrpwm.c
index e3407d0a1f7f..f9dd3b91c73a 100644
--- a/drivers/pwm/pwm-tiehrpwm.c
+++ b/drivers/pwm/pwm-tiehrpwm.c
@@ -461,18 +461,19 @@ static int ehrpwm_pwm_probe(struct platform_device *pdev)
 		return ret;
 	}
 
-	ret = pwmchip_add(chip);
-	if (ret < 0) {
-		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
-		goto err_clk_unprepare;
-	}
-
 	platform_set_drvdata(pdev, chip);
 	pm_runtime_enable(&pdev->dev);
 
+	ret = pwmchip_add(chip);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "pwmchip_add() failed: %d\n", ret);
+		goto err_pm_disable;
+	}
+
 	return 0;
 
-err_clk_unprepare:
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
 	clk_unprepare(pc->tbclk);
 
 	return ret;
Cc: "Philip, Avinash" <avinashphilip@xxxxxx>
-- 
2.56.0.398.g882cbad275-goog