Re: [PATCH v2 4/4] PCI: cadence: Fix to read 32-bit Vendor ID/Device ID property from DT

From: Lorenzo Pieralisi
Date: Mon May 04 2020 - 07:25:48 EST


On Mon, May 04, 2020 at 02:22:30PM +0530, Kishon Vijay Abraham I wrote:
> Hi Lorenzo,
>
> On 5/1/2020 8:41 PM, Lorenzo Pieralisi wrote:
> > On Fri, Apr 17, 2020 at 05:13:22PM +0530, Kishon Vijay Abraham I wrote:
> >> The PCI Bus Binding specification (IEEE Std 1275-1994 Revision 2.1 [1])
> >> defines both Vendor ID and Device ID to be 32-bits. Fix
> >> pcie-cadence-host.c driver to read 32-bit Vendor ID and Device ID
> >> properties from device tree.
> >>
> >> [1] -> https://www.devicetree.org/open-firmware/bindings/pci/pci2_1.pdf
> >>
> >> Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx>
> >> ---
> >> drivers/pci/controller/cadence/pcie-cadence-host.c | 4 ++--
> >> drivers/pci/controller/cadence/pcie-cadence.h | 4 ++--
> >> 2 files changed, 4 insertions(+), 4 deletions(-)
> >
> > I don't see how you would use a 32-bit value for a 16-bit register so
> > certainly the struct cdns_pcie_rc fields size is questionable anyway.
> >
> > I *assume* you are referring to 4.1.2.1 and the property list
> > encoded as "encode-int".
> >
> > I would like to get RobH's opinion on this - I don't know myself
> > whether the PCI OF bindings you added are still relevant and how
> > they should be interpreted.
>
> This change was made due to RobH's comment below [1]
>
> [1] ->
> https://lore.kernel.org/r/CAL_JsqLYScxGySy8xaN-UB6URfw8K_jSiuSXwVoTU9-RdJecww@xxxxxxxxxxxxxx/

Thanks for the pointer - that's what I needed to proceed with this
patch.

Lorenzo

> Thanks
> Kishon
>
> >
> > Thanks
> > Lorenzo
> >
> >> diff --git a/drivers/pci/controller/cadence/pcie-cadence-host.c b/drivers/pci/controller/cadence/pcie-cadence-host.c
> >> index 8f72967f298f..31e67c9c88cf 100644
> >> --- a/drivers/pci/controller/cadence/pcie-cadence-host.c
> >> +++ b/drivers/pci/controller/cadence/pcie-cadence-host.c
> >> @@ -229,10 +229,10 @@ int cdns_pcie_host_setup(struct cdns_pcie_rc *rc)
> >> }
> >>
> >> rc->vendor_id = 0xffff;
> >> - of_property_read_u16(np, "vendor-id", &rc->vendor_id);
> >> + of_property_read_u32(np, "vendor-id", &rc->vendor_id);
> >>
> >> rc->device_id = 0xffff;
> >> - of_property_read_u16(np, "device-id", &rc->device_id);
> >> + of_property_read_u32(np, "device-id", &rc->device_id);
> >>
> >> res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "reg");
> >> pcie->reg_base = devm_ioremap_resource(dev, res);
> >> diff --git a/drivers/pci/controller/cadence/pcie-cadence.h b/drivers/pci/controller/cadence/pcie-cadence.h
> >> index 6bd89a21bb1c..df14ad002fe9 100644
> >> --- a/drivers/pci/controller/cadence/pcie-cadence.h
> >> +++ b/drivers/pci/controller/cadence/pcie-cadence.h
> >> @@ -262,8 +262,8 @@ struct cdns_pcie_rc {
> >> struct resource *bus_range;
> >> void __iomem *cfg_base;
> >> u32 no_bar_nbits;
> >> - u16 vendor_id;
> >> - u16 device_id;
> >> + u32 vendor_id;
> >> + u32 device_id;
> >> };
> >>
> >> /**
> >> --
> >> 2.17.1
> >>