Re: [PATCH v7 07/14] PCI: rzg3s-host: Use cached MSI address in .irq_compose_msi_msg()

[Lad, Prabhakar]

Hi Claudiu,

Thank you for the patch.

On Mon, Oct 19, 2026 at 7:57 AM Claudiu Beznea
<claudiu.beznea@xxxxxxxxxx> wrote:
>
> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
>
> The MSI window address is already cached in msi->window_base when the
> MSI window is configured. Use it to fill msg->address_lo and
> msg->address_hi in .irq_compose_msi_msg() instead of reading it back
> from the controller registers.
>
> This avoids unnecessary register accesses.
>
> Signed-off-by: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx>
> ---
>
> Changes in v7:
> - none, this patch is new
>
>  drivers/pci/controller/pcie-rzg3s-host.c | 14 ++------------
>  1 file changed, 2 insertions(+), 12 deletions(-)
>
> diff --git a/drivers/pci/controller/pcie-rzg3s-host.c b/drivers/pci/controller/pcie-rzg3s-host.c
> index b0a150262959..6acb0231a067 100644
> --- a/drivers/pci/controller/pcie-rzg3s-host.c
> +++ b/drivers/pci/controller/pcie-rzg3s-host.c
> @@ -660,19 +660,9 @@ static void rzg3s_pcie_irq_compose_msi_msg(struct irq_data *data,
>                                            struct msi_msg *msg)
>  {
>         struct rzg3s_pcie_msi *msi = irq_data_get_irq_chip_data(data);
> -       struct rzg3s_pcie_host *host = rzg3s_msi_to_host(msi);
> -       u32 lo, hi;
> -
> -       /*
> -        * Enable and msg data enable bits are part of the address lo. Drop
> -        * them along with the unused bit.
> -        */
> -       lo = readl_relaxed(host->axi + RZG3S_PCI_MSIRCVWADRL) &
> -            RZG3S_PCI_MSIRCVWADRL_MASK;
We need to drop RZG3S_PCI_MSIRCVWADRL_MASK macro, as this now triggers
the below warning:

drivers/pci/controller/pcie-rzg3s-host.c:66:9: warning: macro
‘RZG3S_PCI_MSIRCVWADRL_MASK’ is not used [-Wunused-macros]
   66 | #define RZG3S_PCI_MSIRCVWADRL_MASK              GENMASK(31, 3)

Cheers,
Prabhakar

> -       hi = readl_relaxed(host->axi + RZG3S_PCI_MSIRCVWADRU);
>
> -       msg->address_lo = lo;
> -       msg->address_hi = hi;
> +       msg->address_lo = lower_32_bits(msi->window_base);
> +       msg->address_hi = upper_32_bits(msi->window_base);
>         msg->data = data->hwirq;
>  }
>
> --
> 2.43.0
>
>