[PATCH] phy: qcom: m31-eusb2: clear PLL_EN during init

Elson Serrao elson.serrao at oss.qualcomm.com
Tue Feb 17 12:11:30 PST 2026


The driver currently sets bit 0 of USB_PHY_CFG1 (PLL_EN) during PHY
initialization. According to the M31 EUSB2 PHY hardware documentation,
this bit is intended only for test/debug scenarios and does not control
mission mode operation. Keeping PLL_EN asserted causes the PHY to draw
additional current during USB bus suspend. Clearing this bit results in
lower suspend power consumption without affecting normal operation.

Update the driver to leave PLL_EN cleared as recommended by the hardware
documentation.

Fixes: 9c8504861cc4 ("phy: qcom: Add M31 based eUSB2 PHY driver")
Cc: stable at vger.kernel.org
Signed-off-by: Elson Serrao <elson.serrao at oss.qualcomm.com>
---
 drivers/phy/qualcomm/phy-qcom-m31-eusb2.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c b/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c
index 95cd3175926d..68f1ba8fec4a 100644
--- a/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c
+++ b/drivers/phy/qualcomm/phy-qcom-m31-eusb2.c
@@ -83,7 +83,7 @@ static const struct m31_phy_tbl_entry m31_eusb2_setup_tbl[] = {
 	M31_EUSB_PHY_INIT_CFG(USB_PHY_CFG0, UTMI_PHY_CMN_CTRL_OVERRIDE_EN, 1),
 	M31_EUSB_PHY_INIT_CFG(USB_PHY_UTMI_CTRL5, POR, 1),
 	M31_EUSB_PHY_INIT_CFG(USB_PHY_HS_PHY_CTRL_COMMON0, PHY_ENABLE, 1),
-	M31_EUSB_PHY_INIT_CFG(USB_PHY_CFG1, PLL_EN, 1),
+	M31_EUSB_PHY_INIT_CFG(USB_PHY_CFG1, PLL_EN, 0),
 	M31_EUSB_PHY_INIT_CFG(USB_PHY_FSEL_SEL, FSEL_SEL, 1),
 };
 
-- 
2.34.1




More information about the linux-phy mailing list