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

[Xu Yang]

On Mon, Mar 30, 2026 at 04:19:24PM +0200, Greg KH wrote:
> 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 at 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 for your review.
Because it's imx8ulp specific errata. Let me add more info in the commit message.

Thanks,
Xu Yang