Commit aecb63e8 authored by Stefan Eichenberger's avatar Stefan Eichenberger Committed by Vinod Koul
Browse files

phy: freescale: imx8m-pcie: assert phy reset and perst in power off 



Ensure the PHY reset and perst is asserted during power-off to
guarantee it is in a reset state upon repeated power-on calls. This
resolves an issue where the PHY may not properly initialize during
subsequent power-on cycles. Power-on will deassert the reset at the
appropriate time after tuning the PHY parameters.

During suspend/resume cycles, we observed that the PHY PLL failed to
lock during resume when the CPU temperature increased from 65C to 75C.
The observed errors were:
  phy phy-32f00000.pcie-phy.3: phy poweron failed --> -110
  imx6q-pcie 33800000.pcie: waiting for PHY ready timeout!
  imx6q-pcie 33800000.pcie: PM: dpm_run_callback(): genpd_resume_noirq+0x0/0x80 returns -110
  imx6q-pcie 33800000.pcie: PM: failed to resume noirq: error -110

This resulted in a complete CPU freeze, which is resolved by ensuring
the PHY is in reset during power-on, thus preventing PHY PLL failures.

Cc: stable@vger.kernel.org
Fixes: 1aa97b00 ("phy: freescale: pcie: Initialize the imx8 pcie standalone phy driver")
Signed-off-by: default avatarStefan Eichenberger <stefan.eichenberger@toradex.com>
Reviewed-by: default avatarFrank Li <Frank.Li@nxp.com>
Link: https://lore.kernel.org/r/20250305144355.20364-3-eichest@gmail.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent 97e8a2ff

drivers/phy/freescale/phy-fsl-imx8m-pcie.c

+11 −0
Original line number Diff line number Diff line
@@ -156,6 +156,16 @@ static int imx8_pcie_phy_power_on(struct phy *phy) 
	return ret;

}



static int imx8_pcie_phy_power_off(struct phy *phy)

{

	struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);



	reset_control_assert(imx8_phy->reset);

	reset_control_assert(imx8_phy->perst);



	return 0;

}



static int imx8_pcie_phy_init(struct phy *phy)

{

	struct imx8_pcie_phy *imx8_phy = phy_get_drvdata(phy);
@@ -176,6 +186,7 @@ static const struct phy_ops imx8_pcie_phy_ops = { 
	.init		= imx8_pcie_phy_init,

	.exit		= imx8_pcie_phy_exit,

	.power_on	= imx8_pcie_phy_power_on,

	.power_off	= imx8_pcie_phy_power_off,

	.owner		= THIS_MODULE,

};