[PATCH v2] phy: qcom: qmp-combo: Move pipe_clk on/off to common

From: Val Packett

Date: Sat Feb 28 2026 - 17:08:04 EST


Keep the USB pipe clock working when the phy is in DP-only mode, because
the dwc controller still needs it for USB 2.0 over the same Type-C port.

Tested with the BenQ RD280UA monitor which has a downstream-facing port
for data passthrough that's manually switchable between USB 2 and 3,
corresponding to 4-lane and 2-lane DP respectively.

Note: the suspend/resume callbacks were already gating the enable/disable
of this clock only on init_count and not usb_init_count!

Signed-off-by: Val Packett <val@xxxxxxxxxxxx>
---
See https://lore.kernel.org/all/389ca5d3-a698-4dac-911c-39ba057e3d17@xxxxxxxxxxxxxxxx/ for more info.
BTW https://lore.kernel.org/all/20260205160240.748371-2-loic.poulain@xxxxxxxxxxxxxxxx/ helped with coldplug.

v2: Reorder disables as suggested
v1: https://lore.kernel.org/all/20250927093915.45124-2-val@xxxxxxxxxxxx/
---
drivers/phy/qualcomm/phy-qcom-qmp-combo.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
index 93f1aa10d400..28428a8d1192 100644
--- a/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
+++ b/drivers/phy/qualcomm/phy-qcom-qmp-combo.c
@@ -3691,6 +3691,13 @@ static int qmp_combo_com_init(struct qmp_combo *qmp, bool force)
if (ret)
goto err_assert_reset;

+ /* In DP-only mode, the pipe clk is still required for USB2 */
+ ret = clk_prepare_enable(qmp->pipe_clk);
+ if (ret) {
+ dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
+ return ret;
+ }
+
qphy_setbits(com, QPHY_V3_DP_COM_POWER_DOWN_CTRL, SW_PWRDN);

/* override hardware control for reset of qmp phy */
@@ -3768,6 +3775,7 @@ static int qmp_combo_com_exit(struct qmp_combo *qmp, bool force)

reset_control_bulk_assert(cfg->num_resets, qmp->resets);

+ clk_disable_unprepare(qmp->pipe_clk);
clk_bulk_disable_unprepare(qmp->num_clks, qmp->clks);

regulator_bulk_disable(cfg->num_vregs, qmp->vregs);
@@ -3871,12 +3879,6 @@ static int qmp_combo_usb_power_on(struct phy *phy)

qmp_configure(qmp->dev, serdes, cfg->serdes_tbl, cfg->serdes_tbl_num);

- ret = clk_prepare_enable(qmp->pipe_clk);
- if (ret) {
- dev_err(qmp->dev, "pipe_clk enable failed err=%d\n", ret);
- return ret;
- }
-
/* Tx, Rx, and PCS configurations */
qmp_configure_lane(qmp->dev, tx, cfg->tx_tbl, cfg->tx_tbl_num, 1);
qmp_configure_lane(qmp->dev, tx2, cfg->tx_tbl, cfg->tx_tbl_num, 2);
@@ -3922,8 +3924,6 @@ static int qmp_combo_usb_power_off(struct phy *phy)
struct qmp_combo *qmp = phy_get_drvdata(phy);
const struct qmp_phy_cfg *cfg = qmp->cfg;

- clk_disable_unprepare(qmp->pipe_clk);
-
/* PHY reset */
qphy_setbits(qmp->pcs, cfg->regs[QPHY_SW_RESET], SW_RESET);

--
2.52.0