linux-kernel - [PATCH v2 3/8] phy: qcom-qmp-combo: Extend phy_mutex to all phy

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Message-ID: <20230510031930.1996020-4-quic_bjorande@quicinc.com>
Date:   Tue, 9 May 2023 20:19:25 -0700
From:   Bjorn Andersson <quic_bjorande@...cinc.com>
To:     Vinod Koul <vkoul@...nel.org>,
        Kishon Vijay Abraham I <kishon@...nel.org>,
        Johan Hovold <johan@...nel.org>
CC:     Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        <linux-arm-msm@...r.kernel.org>, <linux-phy@...ts.infradead.org>,
        <devicetree@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: [PATCH v2 3/8] phy: qcom-qmp-combo: Extend phy_mutex to all phy_ops

The phy core ensures mutual exclusion across the ops for a given phy,
but the upcoming introduction of USB Type-C orientation switching might
race with the DisplayPort phy operations. So extend the mutual exclusion
to cover the remaining ops as well, to avoid concurrent reconfiguration
of the hardware.

Reported-by: Johan Hovold <johan@...nel.org>
Signed-off-by: Bjorn Andersson <quic_bjorande@...cinc.com>
---

Changes since v1:
- New patch

 drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 21 +++++++++++++++++++--
 1 file changed, 19 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index 8918ba2b18a4..6baacdf3a4cb 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -2437,12 +2437,16 @@ static int qmp_combo_dp_configure(struct phy *phy, union phy_configure_opts *opt
 	struct qmp_combo *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
 
+	mutex_lock(&qmp->phy_mutex);
+
 	memcpy(&qmp->dp_opts, dp_opts, sizeof(*dp_opts));
 	if (qmp->dp_opts.set_voltages) {
 		cfg->configure_dp_tx(qmp);
 		qmp->dp_opts.set_voltages = 0;
 	}
 
+	mutex_unlock(&qmp->phy_mutex);
+
 	return 0;
 }
 
@@ -2450,11 +2454,16 @@ static int qmp_combo_dp_calibrate(struct phy *phy)
 {
 	struct qmp_combo *qmp = phy_get_drvdata(phy);
 	const struct qmp_phy_cfg *cfg = qmp->cfg;
+	int ret = 0;
+
+	mutex_lock(&qmp->phy_mutex);
 
 	if (cfg->calibrate_dp_phy)
-		return cfg->calibrate_dp_phy(qmp);
+		ret = cfg->calibrate_dp_phy(qmp);
 
-	return 0;
+	mutex_unlock(&qmp->phy_mutex);
+
+	return ret;
 }
 
 static int qmp_combo_com_init(struct qmp_combo *qmp)
@@ -2578,6 +2587,8 @@ static int qmp_combo_dp_power_on(struct phy *phy)
 	void __iomem *tx = qmp->dp_tx;
 	void __iomem *tx2 = qmp->dp_tx2;
 
+	mutex_lock(&qmp->phy_mutex);
+
 	qmp_combo_dp_serdes_init(qmp);
 
 	qmp_combo_configure_lane(tx, cfg->dp_tx_tbl, cfg->dp_tx_tbl_num, 1);
@@ -2589,6 +2600,8 @@ static int qmp_combo_dp_power_on(struct phy *phy)
 	/* Configure link rate, swing, etc. */
 	cfg->configure_dp_phy(qmp);
 
+	mutex_unlock(&qmp->phy_mutex);
+
 	return 0;
 }
 
@@ -2596,9 +2609,13 @@ static int qmp_combo_dp_power_off(struct phy *phy)
 {
 	struct qmp_combo *qmp = phy_get_drvdata(phy);
 
+	mutex_lock(&qmp->phy_mutex);
+
 	/* Assert DP PHY power down */
 	writel(DP_PHY_PD_CTL_PSR_PWRDN, qmp->dp_dp_phy + QSERDES_DP_PHY_PD_CTL);
 
+	mutex_unlock(&qmp->phy_mutex);
+
 	return 0;
 }
 
-- 
2.39.2