Re: [PATCH 2/7] nouveau/gsp: fix HDMI vendor infoframes on GB20x

[lyude@redhat.com]

On Sat, 2026-08-15 at 03:57 +0400, Mohamed Ahmed wrote:
> The GSP path reuses the GV100 direct-MMIO infoframe writers on every
> chip. On GB20x that is only half right as while the legacy SF AVI
> unit is
> unchanged, the legacy VSI unit at 0x6f0100 was removed, so
> gv100_sor_hdmi_infoframe_vsi() writes into a reserved area and no
> vendor
> infoframe ever reaches the wire. This affects HDMI-VIC signalling
> which
> can impact some 4K modes for legacy HDMI 1.4 sinks.
> 
> Select the SOR functions per GPU family in r535_sor_new(), keyed on
> the display root class from the RM GPU table and use the new
> generic-infoframe VSI writer on GB20x. Everything else stays on the
> r535 table.
> 
> Signed-off-by: Mohamed Ahmed <mohamedahmedegypt2001@gmail.com>
> ---
>  .../nouveau/nvkm/subdev/gsp/rm/r535/disp.c    | 29
> ++++++++++++++++++-
>  1 file changed, 28 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
> b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
> index 1155f079b0c3..96febd01da78 100644
> --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
> +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/rm/r535/disp.c
> @@ -36,6 +36,8 @@
>  
>  #include <rm/gpu.h>
>  
> +#include <nvif/class.h>
> +
>  #include <nvhw/drf.h>
>  
>  #include "nvrm/disp.h"
> @@ -587,6 +589,16 @@ r535_sor_hdmi = {
>  	.audio = r535_sor_hdmi_audio,
>  };
>  
> +static const struct nvkm_ior_func_hdmi
> +gb202_sor_hdmi = {
> +	.ctrl = r535_sor_hdmi_ctrl,
> +	/* The legacy AVI unit is unchanged on GB20x. */
> +	.infoframe_avi = gv100_sor_hdmi_infoframe_avi,
> +	.infoframe_vsi = gb202_sor_hdmi_infoframe_vsi,
> +	.audio = r535_sor_hdmi_audio,
> +	.frl_train = r535_sor_frl_train,
> +};
> +

This is the right approach, but I think this might make more sense to
move into drivers/gpu/drm/nouveau/nvkm/subdev/gsp/gb202.c and then
reference it back here.

>  static const struct nvkm_ior_func
>  r535_sor = {
>  	.hdmi = &r535_sor_hdmi,
> @@ -595,10 +607,25 @@ r535_sor = {
>  	.bl = &r535_sor_bl,
>  };
>  
> +static const struct nvkm_ior_func
> +gb202_sor = {
> +	.hdmi = &gb202_sor_hdmi,
> +	.dp = &r535_sor_dp,
> +	.hda = &r535_sor_hda,
> +	.bl = &r535_sor_bl,
> +};
> +
>  static int
>  r535_sor_new(struct nvkm_disp *disp, int id)
>  {
> -	return nvkm_ior_new_(&r535_sor, disp, SOR, id, true/*XXX:
> hda cap*/);
> +	const struct nvkm_rm_gpu *gpu = disp->engine.subdev.device-
> >gsp->rm->gpu;
> +	const struct nvkm_ior_func *func = &r535_sor;
> +
> +	/* NVD5.0 (GB20x and later) reorganised the SF HDMI packet
> units. */
> +	if (gpu->disp.class.root >= GB202_DISP)
> +		func = &gb202_sor;
> +
> +	return nvkm_ior_new_(func, disp, SOR, id, true/*XXX: hda
> cap*/);
>  }
>  
>  static int