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From:   Huacai Chen <chenhuacai@kernel.org>
Date:   Thu, 31 Aug 2023 17:42:51 +0800
Message-ID: <CAAhV-H4DRFrsWOusyVPo5U_F-fwcfUUktGe31x9S3=E7vci=pQ@mail.gmail.com>
Subject: Re: [PATCH v2] pci: loongson: Workaround MIPS firmware MRRS settings
To:     Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc:     linux-pci@vger.kernel.org, bhelgaas@google.com,
        linux-kernel@vger.kernel.org, kw@linux.com, lpieralisi@kernel.org,
        stable@vger.kernel.org
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On Thu, Aug 31, 2023 at 4:58=E2=80=AFPM Jiaxun Yang <jiaxun.yang@flygoat.co=
m> wrote:
>
>
>
> =E5=9C=A8 2023/8/31 14:22, Huacai Chen =E5=86=99=E9=81=93:
>
> [...]
> > But it is worth to try, and you can walk the children to set mrrs when
> > the quirk runs on bridges, I think.
> No, this will break hotplug, I had managed to get hotplug work on 2K1000.
> Also we have no guarantee on order of discovering devices.
> >> but the old quirk should run on every single device.
> > Your current patch has a drawback that both quirks will run for MIPS,
> > and their order is random (though it may cause nothing, but not
> > elegant).
> Actually loongson_mrrs_quirk is declared by DECLARE_PCI_FIXUP_EARLY but
> loongson_old_mrrs_quirk is declared by DECLARE_PCI_FIXUP_ENABLE,
> which means loongson_old_mrrs_quirk always runs after loongson_mrrs_quirk=
 as
> expected.
Then I think it is better to put this quirk in arch/mips/loongson64/,
just as pci_fixup_radeon().

Huacai
>
> Thanks
> - Jiaxun
>
> [...]