> -----Original Message-----
> From: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> Sent: 2025年4月2日 15:10
> 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 5/6] PCI: imx6: Add PLL clock lock check for i.MX95 PCIe
>
> On Fri, Mar 28, 2025 at 11:02:12AM +0800, Richard Zhu wrote:
> > Add PLL clock lock check for i.MX95 PCIe.
> >
>
> What are the implications of not waiting for PLL lock? I guess clock instability.
>
Yes, it is.
> > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx>
> > Reviewed-by: Frank Li <Frank.Li@xxxxxxx>
> > ---
> > drivers/pci/controller/dwc/pci-imx6.c | 28
> > +++++++++++++++++++++++++--
> > 1 file changed, 26 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c
> > b/drivers/pci/controller/dwc/pci-imx6.c
> > index 35194b543551..40eeb02ffb5d 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -45,6 +45,9 @@
> > #define IMX95_PCIE_PHY_GEN_CTRL 0x0
> > #define IMX95_PCIE_REF_USE_PAD BIT(17)
> >
> > +#define IMX95_PCIE_PHY_MPLLA_CTRL 0x10
> > +#define IMX95_PCIE_PHY_MPLL_STATE BIT(30)
> > +
> > #define IMX95_PCIE_SS_RW_REG_0 0xf0
> > #define IMX95_PCIE_REF_CLKEN BIT(23)
> > #define IMX95_PCIE_PHY_CR_PARA_SEL BIT(9)
> > @@ -479,6 +482,23 @@ static void imx7d_pcie_wait_for_phy_pll_lock(struct
> imx_pcie *imx_pcie)
> > dev_err(dev, "PCIe PLL lock timeout\n"); }
> >
> > +static int imx95_pcie_wait_for_phy_pll_lock(struct imx_pcie
> > +*imx_pcie) {
> > + u32 val;
> > + struct device *dev = imx_pcie->pci->dev;
> > +
> > + if (regmap_read_poll_timeout(imx_pcie->iomuxc_gpr,
> > + IMX95_PCIE_PHY_MPLLA_CTRL, val,
> > + val & IMX95_PCIE_PHY_MPLL_STATE,
> > + PHY_PLL_LOCK_WAIT_USLEEP_MAX,
> > + PHY_PLL_LOCK_WAIT_TIMEOUT)) {
> > + dev_err(dev, "PCIe PLL lock timeout\n");
> > + return -ENODEV;
>
> -ETIMEDOUT
Okay
Best Regards
Richard Zhu
>
> - Mani
>
> --
> மணிவண்ணன் சதாசிவம்
