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References: <20220214155518.2980270-1-icenowy@aosc.io>
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From:   Ilia Mirkin <imirkin@alum.mit.edu>
Date:   Mon, 14 Feb 2022 11:07:33 -0500
Message-ID: <CAKb7UvjRoS-z1f6a=p0TknPruZJBKmUEiAFOR9Ka5LgJ765Ybg@mail.gmail.com>
Subject: Re: [PATCH] drm/nouveau/bios: Use HWSQ entry 1 for PowerBook6,1
To:     Icenowy Zheng <icenowy@aosc.io>
Cc:     Ben Skeggs <bskeggs@redhat.com>, David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        nouveau <nouveau@lists.freedesktop.org>,
        LKML <linux-kernel@vger.kernel.org>,
        dri-devel <dri-devel@lists.freedesktop.org>
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I'm not saying this is wrong, but could you file a bug at
gitlab.freedesktop.org/drm/nouveau/-/issues and include the VBIOS
(/sys/kernel/debug/dri/0/vbios.rom)? That would make it easier to
review the full situation.

On Mon, Feb 14, 2022 at 11:03 AM Icenowy Zheng <icenowy@aosc.io> wrote:
>
> On PowerBook6,1 (PowerBook G4 867 12") HWSQ entry 0 (which is currently
> always used by nouveau) fails, but the BIOS declares 2 HWSQ entries and
> entry 1 works.
>
> Add a quirk to use HWSQ entry 1.
>
> Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
> ---
>  drivers/gpu/drm/nouveau/nouveau_bios.c | 7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_bios.c b/drivers/gpu/drm/nouveau/nouveau_bios.c
> index e8c445eb11004..2691d0e0cf9f1 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_bios.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_bios.c
> @@ -1977,6 +1977,13 @@ static int load_nv17_hw_sequencer_ucode(struct drm_device *dev,
>         if (!hwsq_offset)
>                 return 0;
>
> +#ifdef __powerpc__
> +       /* HWSQ entry 0 fails on PowerBook G4 867 12" (Al) */
> +       if (of_machine_is_compatible("PowerBook6,1"))
> +               return load_nv17_hwsq_ucode_entry(dev, bios,
> +                                                 hwsq_offset + sz, 1);
> +#endif
> +
>         /* always use entry 0? */
>         return load_nv17_hwsq_ucode_entry(dev, bios, hwsq_offset + sz, 0);
>  }
> --
> 2.30.2
>