Re: [PATCH v19 09/10] pci: imx6: Add LUT setting for MSI/IOMMU in Endpoint mode

[Frank Li <Frank.li@nxp.com>]

On Wed, Jul 02, 2025 at 06:52:01PM +0530, Manivannan Sadhasivam wrote:
> On Mon, Jun 09, 2025 at 12:34:21PM GMT, Frank Li wrote:
> > Support only one physical function, so call imx_pcie_add_lut_by_rid(0)
> > to add a single LUT entry when operating in EP mode.
> >
>
> So previously LUT config was not present and endpoint mode continued to work?

Yes, LUT only use when enable msi and iommu. I will add such information
at next version.

Frank

> Please explain why this is necessary now.
>
> - Mani
>
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> > change from v14 to v16
> > - none
> >
> > change from v13 to v14
> > - new patch
> > ---
> >  drivers/pci/controller/dwc/pci-imx6.c | 8 +++++++-
> >  1 file changed, 7 insertions(+), 1 deletion(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > index 032b906c44dfa..3123bf49e209c 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -1063,7 +1063,10 @@ static int imx_pcie_add_lut(struct imx_pcie *imx_pcie, u16 rid, u8 sid)
> >  	data1 |= IMX95_PE0_LUT_VLD;
> >  	regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA1, data1);
> >
> > -	data2 = IMX95_PE0_LUT_MASK; /* Match all bits of RID */
> > +	if (imx_pcie->drvdata->mode == DW_PCIE_EP_TYPE)
> > +		data2 = 0x7; /* EP side's RID from RC, only 'D' is meansful */
> > +	else
> > +		data2 = IMX95_PE0_LUT_MASK; /* Match all bits of RID */
> >  	data2 |= FIELD_PREP(IMX95_PE0_LUT_REQID, rid);
> >  	regmap_write(imx_pcie->iomuxc_gpr, IMX95_PE0_LUT_DATA2, data2);
> >
> > @@ -1767,6 +1770,9 @@ static int imx_pcie_probe(struct platform_device *pdev)
> >  		ret = imx_add_pcie_ep(imx_pcie, pdev);
> >  		if (ret < 0)
> >  			return ret;
> > +
> > +		/* Only support one physical function */
> > +		imx_pcie_add_lut_by_rid(imx_pcie, 0);
> >  	} else {
> >  		pci->pp.use_atu_msg = true;
> >  		ret = dw_pcie_host_init(&pci->pp);
> >
> > --
> > 2.34.1
> >
>
> --
> மணிவண்ணன் சதாசிவம்