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@xxxxxxx> 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@xxxxxxx>
> ---
> 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
>
