[PATCH] mfd: stpmic1: Attempt system shutdown twice in case PMIC is confused

[Marek Vasut <marex@nabladev.com>]

Attempt to shut down again, in case the first attempt failed.
The STPMIC1 might get confused and the first regmap_update_bits()
returns with -ETIMEDOUT / -110 . If that or similar transient
failure occurs, try to shut down again. If the second attempt
fails, there is some bigger problem, report it to user.

Fixes: 6e9df38f359a ("mfd: stpmic1: Add PMIC poweroff via sys-off handler")
Signed-off-by: Marek Vasut <marex@nabladev.com>
---
Cc: Lee Jones <lee@kernel.org>
Cc: Pascal PAILLET-LME <p.paillet@st.com>
Cc: Paul Cercueil <paul@crapouillou.net>
Cc: Sean Nyekjaer <sean@geanix.com>
Cc: kernel@dh-electronics.com
---
 drivers/mfd/stpmic1.c | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/drivers/mfd/stpmic1.c b/drivers/mfd/stpmic1.c
index 081827bc05961..9ef4049d7db10 100644
--- a/drivers/mfd/stpmic1.c
+++ b/drivers/mfd/stpmic1.c
@@ -121,9 +121,23 @@ static const struct regmap_irq_chip stpmic1_regmap_irq_chip = {
 static int stpmic1_power_off(struct sys_off_data *data)
 {
 	struct stpmic1 *ddata = data->cb_data;
+	int ret;
+
+	ret = regmap_update_bits(ddata->regmap, MAIN_CR, SOFTWARE_SWITCH_OFF, SOFTWARE_SWITCH_OFF);
+	if (!ret)
+		return NOTIFY_DONE;
+
+	/*
+	 * Attempt to shut down again, in case the first attempt failed.
+	 * The STPMIC1 might get confused and the first regmap_update_bits()
+	 * returns with -ETIMEDOUT / -110 . If that or similar transient
+	 * failure occurs, try to shut down again. If the second attempt
+	 * fails, there is some bigger problem, report it to user.
+	 */
+	ret = regmap_update_bits(ddata->regmap, MAIN_CR, SOFTWARE_SWITCH_OFF, SOFTWARE_SWITCH_OFF);
+	if (ret)
+		dev_err(ddata->dev, "Failed to access PMIC I2C bus (%d)\n", ret);
 
-	regmap_update_bits(ddata->regmap, MAIN_CR,
-			   SOFTWARE_SWITCH_OFF, SOFTWARE_SWITCH_OFF);
 
 	return NOTIFY_DONE;
 }
-- 
2.51.0