Re: [PATCH] usb: phy: mxs: manually reset phy regs after a warm reset

[Greg KH <gregkh@linuxfoundation.org>]

On Mon, Mar 30, 2026 at 05:31:33PM +0800, Xu Yang wrote:
> The usb phy registers are not fully reset on warm reset under stress
> conditions. We need to manually reset those (CTRL, PWD, DEBUG, PLL_SIC)
> regs after a warm reset. This will reset DEBUG and PLL_SIC registers.
> CTRL and PWD register are handled by "SFT" bit in stmp_reset_block().
> 
> ERR051269: USB PHY registers not fully resetting on warm reset under
>            stress conditions
> 
> The following USB PHY registers must be written by SW to restore the reset
> value after a warm reset:
> 
> Reg: ctrl Addr: 0x29910030 Data: 0xc000_0000
> Reg: pwd Addr: 0x29910000 Data: 0x001e_1c00
> Reg: debug0 Addr: 0x29910050 Data: 0x7f18_0000
> Reg: pll_sic Addr: 0x299100a0 Data: 0x00d1_2000
> 
> Signed-off-by: Xu Yang <xu.yang_2@nxp.com>
> ---
>  drivers/usb/phy/phy-mxs-usb.c | 32 +++++++++++++++++++++++++++++---
>  1 file changed, 29 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/phy/phy-mxs-usb.c b/drivers/usb/phy/phy-mxs-usb.c
> index 7069dd3f4d0d..dd42db8a0829 100644
> --- a/drivers/usb/phy/phy-mxs-usb.c
> +++ b/drivers/usb/phy/phy-mxs-usb.c
> @@ -209,6 +209,9 @@ static const struct mxs_phy_data imx6ul_phy_data = {
>  static const struct mxs_phy_data imx7ulp_phy_data = {
>  };
>  
> +static const struct mxs_phy_data imx8ulp_phy_data = {
> +};
> +
>  static const struct of_device_id mxs_phy_dt_ids[] = {
>  	{ .compatible = "fsl,imx6sx-usbphy", .data = &imx6sx_phy_data, },
>  	{ .compatible = "fsl,imx6sl-usbphy", .data = &imx6sl_phy_data, },
> @@ -217,6 +220,7 @@ static const struct of_device_id mxs_phy_dt_ids[] = {
>  	{ .compatible = "fsl,vf610-usbphy", .data = &vf610_phy_data, },
>  	{ .compatible = "fsl,imx6ul-usbphy", .data = &imx6ul_phy_data, },
>  	{ .compatible = "fsl,imx7ulp-usbphy", .data = &imx7ulp_phy_data, },
> +	{ .compatible = "fsl,imx8ulp-usbphy", .data = &imx8ulp_phy_data, },

Why can't you use &imx7ulp_phy_data here as it's all just empty?

thanks,

greg k-h