linux-kernel - [PATCH 1/5] phy: qcom: qmp-pcie: Skip PHY reset if already up

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Message-Id: <20260109-link_retain-v1-1-7e6782230f4b@oss.qualcomm.com>
Date: Fri, 09 Jan 2026 12:51:06 +0530
From: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
To: Vinod Koul <vkoul@...nel.org>, Neil Armstrong <neil.armstrong@...aro.org>,
        Philipp Zabel <p.zabel@...gutronix.de>,
        Jingoo Han <jingoohan1@...il.com>,
        Manivannan Sadhasivam <mani@...nel.org>,
        Lorenzo Pieralisi <lpieralisi@...nel.org>,
        Krzysztof Wilczyński <kwilczynski@...nel.org>,
        Rob Herring <robh@...nel.org>, Bjorn Helgaas <bhelgaas@...gle.com>
Cc: linux-arm-msm@...r.kernel.org, linux-phy@...ts.infradead.org,
        linux-kernel@...r.kernel.org, linux-pci@...r.kernel.org,
        Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
Subject: [PATCH 1/5] phy: qcom: qmp-pcie: Skip PHY reset if already up

If the bootloader has already powered up the PCIe PHY, doing a full
reset and waiting for it to come up again slows down boot time.

Add a check for PHY status and skip the reset steps when the PHY is
already active. In this case, only enable the required resources during
power-on. This works alongside the existing logic that skips the init
sequence.

Signed-off-by: Krishna Chaitanya Chundru <krishna.chundru@....qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-qmp-pcie.c | 28 ++++++++++++++++++----------
 1 file changed, 18 insertions(+), 10 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
index 86b1b7e2da86a8675e3e48e90b782afb21cafd77..c93e613cf80b2612f0f225fa2125f78dbec1a33f 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-pcie.c
@@ -3153,6 +3153,7 @@ struct qmp_pcie {
 	const struct qmp_phy_cfg *cfg;
 	bool tcsr_4ln_config;
 	bool skip_init;
+	bool skip_reset;
 
 	void __iomem *serdes;
 	void __iomem *pcs;
@@ -4537,6 +4538,9 @@ static int qmp_pcie_init(struct phy *phy)
 		qphy_checkbits(pcs, cfg->regs[QPHY_START_CTRL], SERDES_START | PCS_START) &&
 		qphy_checkbits(pcs, cfg->regs[QPHY_PCS_POWER_DOWN_CONTROL], cfg->pwrdn_ctrl);
 
+	qmp->skip_reset = qmp->skip_init && !qphy_checkbits(pcs, cfg->regs[QPHY_PCS_STATUS],
+							    cfg->phy_status);
+
 	if (!qmp->skip_init && !cfg->tbls.serdes_num) {
 		dev_err(qmp->dev, "Init sequence not available\n");
 		return -ENODATA;
@@ -4560,13 +4564,15 @@ static int qmp_pcie_init(struct phy *phy)
 		}
 	}
 
-	ret = reset_control_assert(qmp->nocsr_reset);
-	if (ret) {
-		dev_err(qmp->dev, "no-csr reset assert failed\n");
-		goto err_assert_reset;
-	}
+	if (!qmp->skip_reset) {
+		ret = reset_control_assert(qmp->nocsr_reset);
+		if (ret) {
+			dev_err(qmp->dev, "no-csr reset assert failed\n");
+			goto err_assert_reset;
+		}
 
-	usleep_range(200, 300);
+		usleep_range(200, 300);
+	}
 
 	if (!qmp->skip_init) {
 		ret = reset_control_bulk_deassert(cfg->num_resets, qmp->resets);
@@ -4641,10 +4647,12 @@ static int qmp_pcie_power_on(struct phy *phy)
 	if (ret)
 		return ret;
 
-	ret = reset_control_deassert(qmp->nocsr_reset);
-	if (ret) {
-		dev_err(qmp->dev, "no-csr reset deassert failed\n");
-		goto err_disable_pipe_clk;
+	if (!qmp->skip_reset) {
+		ret = reset_control_deassert(qmp->nocsr_reset);
+		if (ret) {
+			dev_err(qmp->dev, "no-csr reset deassert failed\n");
+			goto err_disable_pipe_clk;
+		}
 	}
 
 	if (qmp->skip_init)

-- 
2.34.1