> -----Original Message-----
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> Sent: 2025年4月2日 15:12
> To: Hongxing Zhu <hongxing.zhu@xxxxxxx>
> Cc: Frank Li <frank.li@xxxxxxx>; l.stach@xxxxxxxxxxxxxx; lpieralisi@xxxxxxxxxx;
> kw@xxxxxxxxx; robh@xxxxxxxxxx; bhelgaas@xxxxxxxxxx;
> shawnguo@xxxxxxxxxx; s.hauer@xxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx;
> festevam@xxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx;
> linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Subject: Re: [PATCH v3 6/6] PCI: imx6: Save and restore the LUT setting for
> i.MX95 PCIe
>
> On Fri, Mar 28, 2025 at 11:02:13AM +0800, Richard Zhu wrote:
> > The look up table(LUT) setting would be lost during PCIe suspend on i.MX95.
> >
> > To ensure proper functionality after resume, save and restore the LUT
> > setting in suspend and resume operations.
> >
>
> There should be a fixes tag pointing to the commit added suspend/resume
> support.
>
Okay, fixes tag would be added later.
Thanks.
Best Regards
Richard Zhu
> > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
>
> - Mani
>
> > ---
> > drivers/pci/controller/dwc/pci-imx6.c | 47
> > +++++++++++++++++++++++++++
> > 1 file changed, 47 insertions(+)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 40eeb02ffb5d..d8f4608eb7da 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -138,6 +138,11 @@ struct imx_pcie_drvdata {
> > const struct dw_pcie_host_ops *ops;
> > };
> >
> > +struct imx_lut_data {
> > + u32 data1;
> > + u32 data2;
> > +};
> > +
> > struct imx_pcie {
> > struct dw_pcie *pci;
> > struct gpio_desc *reset_gpiod;
> > @@ -157,6 +162,8 @@ struct imx_pcie {
> > struct regulator *vph;
> > void __iomem *phy_base;
> >
> > + /* LUT data for pcie */
> > + struct imx_lut_data luts[IMX95_MAX_LUT];
> > /* power domain for pcie */
> > struct device *pd_pcie;
> > /* power domain for pcie phy */
> > @@ -1505,6 +1512,42 @@ static void imx_pcie_msi_save_restore(struct
> imx_pcie *imx_pcie, bool save)
> > }
> > }
> >
> > +static void imx_pcie_lut_save(struct imx_pcie *imx_pcie) {
> > + u32 data1, data2;
> > + int i;
> > +
> > + for (i = 0; i < IMX95_MAX_LUT; i++) {
> > + regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL,
> > + IMX95_PEO_LUT_RWA | i);
> > + regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1,
> &data1);
> > + regmap_read(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2,
> &data2);
> > + if (data1 & IMX95_PE0_LUT_VLD) {
> > + imx_pcie->luts[i].data1 = data1;
> > + imx_pcie->luts[i].data2 = data2;
> > + } else {
> > + imx_pcie->luts[i].data1 = 0;
> > + imx_pcie->luts[i].data2 = 0;
> > + }
> > + }
> > +}
> > +
> > +static void imx_pcie_lut_restore(struct imx_pcie *imx_pcie) {
> > + int i;
> > +
> > + for (i = 0; i < IMX95_MAX_LUT; i++) {
> > + if ((imx_pcie->luts[i].data1 & IMX95_PE0_LUT_VLD) == 0)
> > + continue;
> > +
> > + regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1,
> > + imx_pcie->luts[i].data1);
> > + regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2,
> > + imx_pcie->luts[i].data2);
> > + regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_ACSCTRL, i);
> > + }
> > +}
> > +
> > static int imx_pcie_suspend_noirq(struct device *dev) {
> > struct imx_pcie *imx_pcie = dev_get_drvdata(dev); @@ -1513,6 +1556,8
> > @@ static int imx_pcie_suspend_noirq(struct device *dev)
> > return 0;
> >
> > imx_pcie_msi_save_restore(imx_pcie, true);
> > + if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
> > + imx_pcie_lut_save(imx_pcie);
> > if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_BROKEN_SUSPEND)) {
> > /*
> > * The minimum for a workaround would be to set PERST# and to
> @@
> > -1557,6 +1602,8 @@ static int imx_pcie_resume_noirq(struct device *dev)
> > if (ret)
> > return ret;
> > }
> > + if (imx_check_flag(imx_pcie, IMX_PCIE_FLAG_HAS_LUT))
> > + imx_pcie_lut_restore(imx_pcie);
> > imx_pcie_msi_save_restore(imx_pcie, false);
> >
> > return 0;
> > --
> > 2.37.1
> >
>
> --
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