[PATCH v1 3/5] PCI: imx6: Workaround i.MX95 PCIe may not exit L23 ready

[Hongxing Zhu]

> -----Original Message-----
> From: Frank Li <frank.li at nxp.com>
> Sent: 2025年3月25日 3:14
> To: Hongxing Zhu <hongxing.zhu at nxp.com>
> Cc: l.stach at pengutronix.de; lpieralisi at kernel.org; kw at linux.com;
> manivannan.sadhasivam at linaro.org; robh at kernel.org;
> bhelgaas at google.com; shawnguo at kernel.org; s.hauer at pengutronix.de;
> kernel at pengutronix.de; festevam at gmail.com; linux-pci at vger.kernel.org;
> linux-arm-kernel at lists.infradead.org; imx at lists.linux.dev;
> linux-kernel at vger.kernel.org
> Subject: Re: [PATCH v1 3/5] PCI: imx6: Workaround i.MX95 PCIe may not exit
> L23 ready
> 
> On Mon, Mar 24, 2025 at 02:26:45PM +0800, Richard Zhu wrote:
> > Workaround for ERR051624: The Controller Without Vaux Cannot Exit L23
> 
> provide a errata link here.
Up to now, I only get the following document updates information.
" This is being converted to Docs update and will be added to init sequence
 in Reference Manual."
Would add the errata link after I find it.
Thanks.

Best Regards
Richard Zhu
> 
> ERR051624: ...
> 
> The words after ERR051624 is descript errata itself, not workaround.
> 
> > Ready Through Beacon or PERST# De-assertion
> >
> > When the auxiliary power is not available, the controller cannot exit
> > from L23 Ready with beacon or PERST# de-assertion when main power is
> > not removed.
> >
> > Workaround: Set SS_RW_REG_1[SYS_AUX_PWR_DET] to 1.
> >
> > Signed-off-by: Richard Zhu <hongxing.zhu at nxp.com>
> > ---
> >  drivers/pci/controller/dwc/pci-imx6.c | 15 +++++++++++++++
> >  1 file changed, 15 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 0f42ab63f5ad..52aa8bd66cde 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -48,6 +48,8 @@
> >  #define IMX95_PCIE_SS_RW_REG_0			0xf0
> >  #define IMX95_PCIE_REF_CLKEN			BIT(23)
> >  #define IMX95_PCIE_PHY_CR_PARA_SEL		BIT(9)
> > +#define IMX95_PCIE_SS_RW_REG_1			0xf4
> > +#define IMX95_PCIE_SYS_AUX_PWR_DET		BIT(31)
> >
> >  #define IMX95_PE0_GEN_CTRL_1			0x1050
> >  #define IMX95_PCIE_DEVICE_TYPE			GENMASK(3, 0)
> > @@ -227,6 +229,19 @@ static unsigned int imx_pcie_grp_offset(const
> > struct imx_pcie *imx_pcie)
> >
> >  static int imx95_pcie_init_phy(struct imx_pcie *imx_pcie)  {
> > +	/*
> > +	 * Workaround for ERR051624: The Controller Without Vaux Cannot
> > +	 * Exit L23 Ready Through Beacon or PERST# De-assertion
> > +	 *
> > +	 * When the auxiliary power is not available, the controller
> > +	 * cannot exit from L23 Ready with beacon or PERST# de-assertion
> > +	 * when main power is not removed.
> > +	 *
> > +	 * Workaround: Set SS_RW_REG_1[SYS_AUX_PWR_DET] to 1.
> > +	 */
> > +	regmap_update_bits(imx_pcie->iomuxc_gpr,
> IMX95_PCIE_SS_RW_REG_1,
> > +			IMX95_PCIE_SYS_AUX_PWR_DET,
> IMX95_PCIE_SYS_AUX_PWR_DET);
> 
> regmap_set_bits()
> 
> Frank
> > +
> >  	regmap_update_bits(imx_pcie->iomuxc_gpr,
> >  			IMX95_PCIE_SS_RW_REG_0,
> >  			IMX95_PCIE_PHY_CR_PARA_SEL,
> > --
> > 2.37.1
> >