Re: [PATCH 2/2] MIPS: Malta: Fix PCI southbridge legacy resource reservations

[Jonas Gorski]

Hi,

On Tue, Oct 21, 2025 at 9:38 PM Maciej W. Rozycki <macro@xxxxxxxxxxx> wrote:
>
> Covering the PCI southbridge legacy port I/O range with a northbridge
> resource reservation prevents MIPS Malta platform code from claiming its
> standard legacy resources.  This is because request_resource() calls
> cause a clash with the previous reservation and consequently fail.
>
> Change to using insert_resource() so as to prevent the clash, switching
> the legacy reservations from:
>
> 00000000-00ffffff : MSC PCI I/O
>   00000020-00000021 : pic1
>   00000070-00000077 : rtc0
>   000000a0-000000a1 : pic2
>   [...]
>
> to:
>
> 00000000-00ffffff : MSC PCI I/O
>   00000000-0000001f : dma1
>   00000020-00000021 : pic1
>   00000040-0000005f : timer
>   00000060-0000006f : keyboard
>   00000070-00000077 : rtc0
>   00000080-0000008f : dma page reg
>   000000a0-000000a1 : pic2
>   000000c0-000000df : dma2
>   [...]
>
> Signed-off-by: Maciej W. Rozycki <macro@xxxxxxxxxxx>
> Fixes: ae81aad5c2e1 ("MIPS: PCI: Use pci_enable_resources()")
> Cc: stable@xxxxxxxxxxxxxxx # v6.18+
> ---
>  arch/mips/mti-malta/malta-setup.c |    2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> linux-mips-malta-setup-insert-resource.diff
> Index: linux-macro/arch/mips/mti-malta/malta-setup.c
> ===================================================================
> --- linux-macro.orig/arch/mips/mti-malta/malta-setup.c
> +++ linux-macro/arch/mips/mti-malta/malta-setup.c
> @@ -213,7 +213,7 @@ void __init plat_mem_setup(void)
>
>         /* Request I/O space for devices used on the Malta board. */

This comment doesn't match the code anymore.

>         for (i = 0; i < ARRAY_SIZE(standard_io_resources); i++)
> -               request_resource(&ioport_resource, standard_io_resources+i);
> +               insert_resource(&ioport_resource, standard_io_resources + i);
>
>         /*
>          * Enable DMA channel 4 (cascade channel) in the PIIX4 south bridge.
>

Best regards,
Jonas