Re: [PATCH 3/5] drm/nouveau/nvkm: introduce new GSP reply policy NVKM_GSP_RPC_REPLY_POLL

[Danilo Krummrich <dakr@kernel.org>]

On Wed, Feb 12, 2025 at 03:57:38PM +0900, Alexandre Courbot wrote:
> On Sat Feb 8, 2025 at 2:58 AM JST, Zhi Wang wrote:
> > There can be multiple cases of handling the GSP RPC messages, which
> > are the reply of GSP RPC commands according to the requirement of the
> > callers and the nature of the GSP RPC commands.
> >
> > Some GSP RPC command needs a new reply policy: "caller don't care about
> > the message content but want to make sure a reply is received". To
> > support this case, a new reply policy is introduced.
> >
> > Introduce new reply policy NVKM_GSP_RPC_REPLY_POLL, which waits for the
> > returned GSP message but discards it for the caller.
> >
> > No functional change is intended.
> >
> > Signed-off-by: Zhi Wang <zhiw@nvidia.com>
> > ---
> >  drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h | 1 +
> >  drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c    | 3 +++
> >  2 files changed, 4 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h b/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h
> > index c467e44cab47..bc16510261b8 100644
> > --- a/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h
> > +++ b/drivers/gpu/drm/nouveau/include/nvkm/subdev/gsp.h
> > @@ -33,6 +33,7 @@ typedef void (*nvkm_gsp_event_func)(struct nvkm_gsp_event *, void *repv, u32 rep
> >  
> >  enum {
> >  	NVKM_GSP_RPC_REPLY_RECV = 1,
> > +	NVKM_GSP_RPC_REPLY_POLL,
> >  };
> >  
> >  struct nvkm_gsp {
> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
> > index bc8eb9a3cb28..af2836cca38f 100644
> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
> > @@ -601,6 +601,9 @@ r535_gsp_rpc_handle_reply(struct nvkm_gsp *gsp, u32 fn, int reply,
> >  		else
> >  			repv = msg;
> >  		break;
> > +	case NVKM_GSP_RPC_REPLY_POLL:
> > +		repv = r535_gsp_msg_recv(gsp, fn, 0);
> > +		break;
> >  	default:
> >  		repv = ERR_PTR(-EINVAL);
> >  		break;
> 
> I suspect patch 4 can be merged into this one, so we introduce the user
> at the same time as the functionality.

I agree, please merge this one with patch 4 and add the corresponding 'Fixes'
tag.