Re: [PATCH 3/4] MIPS: PCI: Return PCIBIOS_* from tx4927_pci_config_read/write()

[Sergio Paracuellos]

Hi,

On Mon, Feb 5, 2024 at 3:35 PM Ilpo Järvinen
<ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:
>
> pci_ops .read/.write must return PCIBIOS_* codes but
> tx4927_pci_config_read/write() return -1 when mkaddr() cannot find
> devfn from the root bus. Return PCIBIOS_DEVICE_NOT_FOUND instead and
> pass that onward in the call chain instead of overwriting the return
> value.
>
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> ---
>  arch/mips/pci/ops-tx4927.c | 14 +++++++++-----
>  1 file changed, 9 insertions(+), 5 deletions(-)
>
> diff --git a/arch/mips/pci/ops-tx4927.c b/arch/mips/pci/ops-tx4927.c
> index f7802f100401..4dd8b93985fb 100644
> --- a/arch/mips/pci/ops-tx4927.c
> +++ b/arch/mips/pci/ops-tx4927.c
> @@ -60,7 +60,7 @@ static int mkaddr(struct pci_bus *bus, unsigned int devfn, int where,
>  {
>         if (bus->parent == NULL &&
>             devfn >= PCI_DEVFN(TX4927_PCIC_MAX_DEVNU, 0))
> -               return -1;
> +               return PCIBIOS_DEVICE_NOT_FOUND;
>         __raw_writel(((bus->number & 0xff) << 0x10)
>                      | ((devfn & 0xff) << 0x08) | (where & 0xfc)
>                      | (bus->parent ? 1 : 0),

Should we also return PCIBIOS_SUCCESSFUL instead of 'return 0' in
'mkaddr' for coherency?

Other than that, changes look good to me.

Reviewed-by: Sergio Paracuellos <sergio.paracuellos@xxxxxxxxx>

Thanks,
    Sergio Paracuellos

> @@ -140,10 +140,12 @@ static int tx4927_pci_config_read(struct pci_bus *bus, unsigned int devfn,
>                                   int where, int size, u32 *val)
>  {
>         struct tx4927_pcic_reg __iomem *pcicptr = pci_bus_to_pcicptr(bus);
> +       int ret;
>
> -       if (mkaddr(bus, devfn, where, pcicptr)) {
> +       ret = mkaddr(bus, devfn, where, pcicptr);
> +       if (ret != PCIBIOS_SUCCESSFUL) {
>                 *val = 0xffffffff;
> -               return -1;
> +               return ret;
>         }
>         switch (size) {
>         case 1:
> @@ -162,9 +164,11 @@ static int tx4927_pci_config_write(struct pci_bus *bus, unsigned int devfn,
>                                    int where, int size, u32 val)
>  {
>         struct tx4927_pcic_reg __iomem *pcicptr = pci_bus_to_pcicptr(bus);
> +       int ret;
>
> -       if (mkaddr(bus, devfn, where, pcicptr))
> -               return -1;
> +       ret = mkaddr(bus, devfn, where, pcicptr);
> +       if (ret != PCIBIOS_SUCCESSFUL)
> +               return ret;
>         switch (size) {
>         case 1:
>                 icd_writeb(val, where & 3, pcicptr);
> --
> 2.39.2
>
>