[PATCH v3 2/2] phy: qcom: qmp-combo: check qmp_combo_com_init() in the typec callbacks

[Oleg Keri]

qmp_combo_typec_switch_set() and qmp_combo_reconfigure_phy(), which the
typec mux callback and the USB4 init path use, tear the common block down
and bring it straight back up on an orientation or altmode change, but
they discard the result of the bringup:

	qmp_combo_com_exit(qmp, true);

	qmp->qmpphy_mode = new_mode;

	/* Now everything's powered down, power up the right PHYs */
	qmp_combo_com_init(qmp, true);

	if ((qmp->usb_init_count || qmp->usb4_init_count) &&
	    new_mode != QMPPHY_MODE_DP_ONLY)
		qmp_combo_usb_power_on(qmp->usb_phy);

If qmp_combo_com_init() fails - a regulator, a reset or
clk_bulk_prepare_enable() - it unwinds what it had brought up and returns
an error, leaving the clocks disabled.  Both paths then carry on and
qmp_combo_usb_power_on(), and dp_aux_init() after it, write PHY registers
with no clock running.  qmp_combo_usb4_init() already checks the return
value of qmp_combo_reconfigure_phy(), but never sees a failure from it.

Propagate the failure instead.  Both callbacks record the requested mode
or orientation before the bringup, and skip the hardware entirely when
the next event asks for what is already recorded, so on failure put the
previous mode back and forget the orientation: the next Type-C event for
the same setting then runs the bringup again instead of being treated as
done.

The PHY is still left logically initialised with its clocks off until
that retry, which is the state any forced bringup failure already
produces and which these callbacks have no way to report to the PHY
consumers; what changes is that the register writes that would fault no
longer happen here.

Fixes: 2851117f8f42 ("phy: qcom-qmp-combo: Introduce orientation switching")
Signed-off-by: Oleg Keri <okerixx@xxxxxxxxx>
---
 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index f6d3320a59d9..ccdf71730dc7 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -4601,6 +4601,9 @@ static int qmp_combo_usb_set_mode(struct phy *phy, enum phy_mode mode, int submo
 
 static int qmp_combo_reconfigure_phy(struct qmp_combo *qmp, enum qmpphy_mode new_mode)
 {
+	enum qmpphy_mode old_mode = qmp->qmpphy_mode;
+	int ret;
+
 	dev_dbg(qmp->dev, "qmp_combo_reconfigure_phy: switching from qmpphy mode %d to %d\n",
 		qmp->qmpphy_mode, new_mode);
 
@@ -4615,7 +4618,11 @@ static int qmp_combo_reconfigure_phy(struct qmp_combo *qmp, enum qmpphy_mode new
 	qmp->qmpphy_mode = new_mode;
 
 	/* Now everything's powered down, power up the right PHYs */
-	qmp_combo_com_init(qmp, true);
+	ret = qmp_combo_com_init(qmp, true);
+	if (ret) {
+		qmp->qmpphy_mode = old_mode;
+		return ret;
+	}
 
 	if ((qmp->usb_init_count || qmp->usb4_init_count) &&
 	    new_mode != QMPPHY_MODE_DP_ONLY)
@@ -5166,6 +5173,7 @@ static int qmp_combo_typec_switch_set(struct typec_switch_dev *sw,
 {
 	struct qmp_combo *qmp = typec_switch_get_drvdata(sw);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	int ret;
 
 	if (qmp->qmpphy_mode == QMPPHY_MODE_USB4) {
 		/* QMPPHY has no orientation handling in USB4 mode, don't cache the setting */
@@ -5186,7 +5194,12 @@ static int qmp_combo_typec_switch_set(struct typec_switch_dev *sw,
 			qmp_combo_usb_power_off(qmp->usb_phy);
 		qmp_combo_com_exit(qmp, true);
 
-		qmp_combo_com_init(qmp, true);
+		ret = qmp_combo_com_init(qmp, true);
+		if (ret) {
+			qmp->orientation = TYPEC_ORIENTATION_NONE;
+			return ret;
+		}
+
 		if (qmp->usb_init_count || qmp->usb4_init_count)
 			qmp_combo_usb_power_on(qmp->usb_phy);
 		if (qmp->dp_init_count)
-- 
2.55.0