From: Stefan Eichenberger stefan.eichenberger@toradex.com

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: 1aa97b002258 ("phy: freescale: pcie: Initialize the imx8 pcie standalone phy driver") Reviewed-by: Frank Li Frank.Li@nxp.com Acked-by: Richard Zhu hongxing.zhu@nxp.com Signed-off-by: Stefan Eichenberger stefan.eichenberger@toradex.com --- drivers/phy/freescale/phy-fsl-imx8m-pcie.c | 11 +++++++++++ 1 file changed, 11 insertions(+)

diff --git a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c index 5b505e34ca364..7355d9921b646 100644 --- a/drivers/phy/freescale/phy-fsl-imx8m-pcie.c +++ b/drivers/phy/freescale/phy-fsl-imx8m-pcie.c @@ -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, };