Re: [PATCH v9 05/16] PCI: imx6: Using "linux,pci-domain" as slot ID

Frank Li
2024-02-02T13:26:10Z

On Fri, Feb 02, 2024 at 01:12:41PM +0100, Lorenzo Pieralisi wrote:
> "PCI: imx6: Use "linux,pci-domain" as slot ID"
>
> On Fri, Jan 19, 2024 at 12:11:11PM -0500, Frank Li wrote:
> > Avoid use get slot id by compared with register physical address. If there
> > are more than 2 slots, compared logic will become complex.
> >
> > "linux,pci-domain" already exist at dts since commit:
> > commit (c0b70f05c87f3b arm64: dts: imx8mq: use_dt_domains for pci node).
> >
> > So it is safe to remove compare basic address code:
> > ...
> > if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> > imx6_pcie->controller_id = 1;
>
> No it is not unless you magically update all firmware out
> there in the field.

commit c0b70f05c87f3b09b391027c6f056d0facf331ef
Author: Peng Fan <peng.fan@nxp.com>
AuthorDate: Fri Jan 15 11:26:57 2021 +0800
Commit: Shawn Guo <shawnguo@kernel.org>
CommitDate: Fri Jan 29 14:46:28 2021 +0800

I am not sure if it is neccesary to compatible with 2 years ago's dts.
I think it may not boot at all with using 2 year agao dtb file directly.

Do you have other comments? I can remove it from this big patch series,

Frank
>
> > ...
> >
> > Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> > Signed-off-by: Frank Li <Frank.Li@nxp.com>
> > ---
> >
> > Notes:
> > Change from v7 to v8
> > - fixed comments
> > - Added Manivannan Sadhasivam's review tag
> > Change from v5 to v7
> > - none
> > Change from v3 to v4
> > - remove compare basic address logic
> > Change from v2 to v3
> > - none
> > Change from v1 to v2
> > - fix of_get_pci_domain_nr return value check logic
> >
> > drivers/pci/controller/dwc/pci-imx6.c | 20 ++++++++++++--------
> > 1 file changed, 12 insertions(+), 8 deletions(-)
> >
> > diff --git a/drivers/pci/controller/dwc/pci-imx6.c b/drivers/pci/controller/dwc/pci-imx6.c
> > index eda6bc6ef80ee..773411d20329f 100644
> > --- a/drivers/pci/controller/dwc/pci-imx6.c
> > +++ b/drivers/pci/controller/dwc/pci-imx6.c
> > @@ -33,6 +33,7 @@
> > #include <linux/pm_domain.h>
> > #include <linux/pm_runtime.h>
> >
> > +#include "../../pci.h"
> > #include "pcie-designware.h"
> >
> > #define IMX8MQ_GPR_PCIE_REF_USE_PAD BIT(9)
> > @@ -40,7 +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 to_imx6_pcie(x) dev_get_drvdata((x)->dev)
> >
> > @@ -1279,13 +1279,17 @@ static int imx6_pcie_probe(struct platform_device *pdev)
> > "Failed to get PCIEPHY reset control\n");
> > }
> >
> > - switch (imx6_pcie->drvdata->variant) {
> > - case IMX7D:
> > - if (dbi_base->start == IMX8MQ_PCIE2_BASE_ADDR)
> > - imx6_pcie->controller_id = 1;
> > - default:
> > - break;
> > - }
> > + /* Using linux,pci-domain as PCI slot id */
> > + imx6_pcie->controller_id = of_get_pci_domain_nr(node);
> > + /*
> > + * If there are no "linux,pci-domain" property specified in DT, then assume only one
> > + * controller is available.
> > + */
> > + if (imx6_pcie->controller_id == -EINVAL)
> > + imx6_pcie->controller_id = 0;
>
> See above, this breaks compatibility with old DTs (and -EINVAL is not
> the only error code you should handle).
>
> Lorenzo
>
> > + else if (imx6_pcie->controller_id < 0)
> > + return dev_err_probe(dev, imx6_pcie->controller_id,
> > + "linux,pci-domain have wrong value\n");
> >
> > /* Grab turnoff reset */
> > imx6_pcie->turnoff_reset = devm_reset_control_get_optional_exclusive(dev, "turnoff");
> > --
> > 2.34.1
> >