On Wed, Mar 12, 2025 at 09:28:02AM +0100, Lucas Stach wrote: > Am Mittwoch, dem 12.03.2025 um 04:05 +0000 schrieb Hongxing Zhu: > > > -----Original Message----- > > > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > > > Sent: 2025年3月11日 23:55 > > > To: Hongxing Zhu <hongxing.zhu@xxxxxxx> > > > Cc: robh@xxxxxxxxxx; krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; > > > shawnguo@xxxxxxxxxx; l.stach@xxxxxxxxxxxxxx; lpieralisi@xxxxxxxxxx; > > > kw@xxxxxxxxx; manivannan.sadhasivam@xxxxxxxxxx; bhelgaas@xxxxxxxxxx; > > > s.hauer@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; devicetree@xxxxxxxxxxxxxxx; > > > linux-pci@xxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; > > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > > > Subject: Re: [PATCH v1 2/2] PCI: imx6: Use domain number replace the > > > hardcodes > > > > > > On Tue, Mar 11, 2025 at 01:11:04AM +0000, Hongxing Zhu wrote: > > > > > -----Original Message----- > > > > > From: Bjorn Helgaas <helgaas@xxxxxxxxxx> > > > > > Sent: 2025年3月10日 23:11 > > > > > To: Hongxing Zhu <hongxing.zhu@xxxxxxx> > > > > > Cc: robh@xxxxxxxxxx; krzk+dt@xxxxxxxxxx; conor+dt@xxxxxxxxxx; > > > > > shawnguo@xxxxxxxxxx; l.stach@xxxxxxxxxxxxxx; lpieralisi@xxxxxxxxxx; > > > > > kw@xxxxxxxxx; manivannan.sadhasivam@xxxxxxxxxx; > > > bhelgaas@xxxxxxxxxx; > > > > > s.hauer@xxxxxxxxxxxxxx; festevam@xxxxxxxxx; > > > > > devicetree@xxxxxxxxxxxxxxx; linux-pci@xxxxxxxxxxxxxxx; > > > > > imx@xxxxxxxxxxxxxxx; kernel@xxxxxxxxxxxxxx; > > > > > linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx > > > > > Subject: Re: [PATCH v1 2/2] PCI: imx6: Use domain number replace the > > > > > hardcodes > > > > > > > > > > On Wed, Feb 26, 2025 at 10:42:56AM +0800, Richard Zhu wrote: > > > > > > Use the domain number replace the hardcodes to uniquely identify > > > > > > different controller on i.MX8MQ platforms. No function changes. > > > > > > > > > > > > Signed-off-by: Richard Zhu <hongxing.zhu@xxxxxxx> > > > > > > --- > > > > > > drivers/pci/controller/dwc/pci-imx6.c | 14 ++++++-------- > > > > > > 1 file changed, 6 insertions(+), 8 deletions(-) > > > > > > > > > > > > diff --git a/drivers/pci/controller/dwc/pci-imx6.c > > > > > > b/drivers/pci/controller/dwc/pci-imx6.c > > > > > > index 90ace941090f..ab9ebb783593 100644 > > > > > > --- a/drivers/pci/controller/dwc/pci-imx6.c > > > > > > +++ b/drivers/pci/controller/dwc/pci-imx6.c > > > > > > @@ -41,7 +41,6 @@ > > > > > > #define IMX8MQ_GPR_PCIE_CLK_REQ_OVERRIDE BIT(11) > > > > > > #define IMX8MQ_GPR_PCIE_VREG_BYPASS BIT(12) > > > > > > #define IMX8MQ_GPR12_PCIE2_CTRL_DEVICE_TYPE GENMASK(11, > > > 8) > > > > > > -#define IMX8MQ_PCIE2_BASE_ADDR 0x33c00000 > > > > > > > > > > > > #define IMX95_PCIE_PHY_GEN_CTRL 0x0 > > > > > > #define IMX95_PCIE_REF_USE_PAD BIT(17) > > > > > > @@ -1474,7 +1473,6 @@ static int imx_pcie_probe(struct > > > > > > platform_device > > > > > *pdev) > > > > > > struct dw_pcie *pci; > > > > > > struct imx_pcie *imx_pcie; > > > > > > struct device_node *np; > > > > > > - struct resource *dbi_base; > > > > > > struct device_node *node = dev->of_node; > > > > > > int i, ret, req_cnt; > > > > > > u16 val; > > > > > > @@ -1515,10 +1513,6 @@ static int imx_pcie_probe(struct > > > > > platform_device *pdev) > > > > > > return PTR_ERR(imx_pcie->phy_base); > > > > > > } > > > > > > > > > > > > - pci->dbi_base = devm_platform_get_and_ioremap_resource(pdev, > > > 0, > > > > > &dbi_base); > > > > > > - if (IS_ERR(pci->dbi_base)) > > > > > > - return PTR_ERR(pci->dbi_base); > > > > > > > > > > This makes me wonder. > > > > > > > > > > IIUC this means that previously we set controller_id to 1 if the > > > > > first item in devicetree "reg" was 0x33c00000, and now we will set > > > > > controller_id to 1 if the devicetree "linux,pci-domain" property is 1. > > > > > This is good, but I think this new dependency on the correct > > > > > "linux,pci-domain" in devicetree should be mentioned in the commit log. > > > > > > > > > > My bigger worry is that we no longer set pci->dbi_base at all. I > > > > > see that the only use of pci->dbi_base in pci-imx6.c was to > > > > > determine the controller_id, but this is a DWC-based driver, and the > > > > > DWC core certainly uses > > > > > pci->dbi_base. Are we sure that none of those DWC core paths are > > > > > important to pci-imx6.c? > > > > Hi Bjorn: > > > > Thanks for your concerns. > > > > Don't worry about the assignment of pci->dbi_base. > > > > If pci-imx6.c driver doesn't set it. DWC core driver would set it when > > > > dw_pcie_get_resources() is invoked. > > > > > > Great, thanks! Maybe we can amend the commit log to mention that and > > > the new "linux,pci-domain" dependency. > > How about the following updates of the commit log? > > > > Use the domain number replace the hardcodes to uniquely identify > > different controller on i.MX8MQ platforms. No function changes. > > Please make sure the " linux,pci-domain" is set for i.MX8MQ correctly, since > > the controller id is relied on it totally. > > > This breaks running a new kernel on an old DT without the > linux,pci-domain property, which I'm absolutely no fan of. We tried > really hard to keep this way around working in the i.MX world. 8MQ already add linux,pci-domain since Jan, 2021 commit c0b70f05c87f3b09b391027c6f056d0facf331ef Author: Peng Fan <peng.fan@xxxxxxx> Date: Fri Jan 15 11:26:57 2021 +0800 Only missed is pcie-ep side, which have not been used at all boards dts file in upstream. Frank > > I'm fine with using the property if present and even mandating it for > new platforms, but getting rid of the existing code for the i.MX8MQ > platform is only a marginal cleanup of the driver code with the obvious > downside of the above breakage. > > Regards, > Lucas
