Nouveau - Oct 2024 - [PATCH v3 10/15] nvkm: refine the variable names in r535_gsp_msg_recv()

The variable "msg" in r535_gsp_msg_recv() actually means the GSP RPC.

Refine the names to align with the terms in the kernel doc.

No functional change is intended.

Signed-off-by: Zhi Wang <zhiw at nvidia.com>
---
 .../gpu/drm/nouveau/nvkm/subdev/gsp/r535.c    | 47 ++++++++++---------
 1 file changed, 24 insertions(+), 23 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
index 2ac0868eb30c..c4164d79240c 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/gsp/r535.c
@@ -336,59 +336,60 @@ static struct nvfw_gsp_rpc *
 r535_gsp_msg_recv(struct nvkm_gsp *gsp, int fn, u32 gsp_rpc_len)
 {
 	struct nvkm_subdev *subdev = &gsp->subdev;
-	struct nvfw_gsp_rpc *msg;
+	struct nvfw_gsp_rpc *rpc;
 	int time = 4000000, i;
 	u32 size;
 
 retry:
-	msg = r535_gsp_msgq_wait(gsp, sizeof(*msg), &size, &time);
-	if (IS_ERR_OR_NULL(msg))
-		return msg;
+	rpc = r535_gsp_msgq_wait(gsp, sizeof(*rpc), &size, &time);
+	if (IS_ERR_OR_NULL(rpc))
+		return rpc;
 
-	msg = r535_gsp_msgq_recv(gsp, msg->length, &time);
-	if (IS_ERR_OR_NULL(msg))
-		return msg;
+	rpc = r535_gsp_msgq_recv(gsp, rpc->length, &time);
+	if (IS_ERR_OR_NULL(rpc))
+		return rpc;
 
-	if (msg->rpc_result) {
-		r535_gsp_msg_dump(gsp, msg, NV_DBG_ERROR);
-		r535_gsp_msg_done(gsp, msg);
+	if (rpc->rpc_result) {
+		r535_gsp_msg_dump(gsp, rpc, NV_DBG_ERROR);
+		r535_gsp_msg_done(gsp, rpc);
 		return ERR_PTR(-EINVAL);
 	}
 
-	r535_gsp_msg_dump(gsp, msg, NV_DBG_TRACE);
+	r535_gsp_msg_dump(gsp, rpc, NV_DBG_TRACE);
 
-	if (fn && msg->function == fn) {
+	if (fn && rpc->function == fn) {
 		if (gsp_rpc_len) {
-			if (msg->length < sizeof(*msg) + gsp_rpc_len) {
-				nvkm_error(subdev, "msg len %d < %zd\n",
-					   msg->length, sizeof(*msg) +
+			if (rpc->length < sizeof(*rpc) + gsp_rpc_len) {
+				nvkm_error(subdev, "rpc len %d < %zd\n",
+					   rpc->length, sizeof(*rpc) +
 					   gsp_rpc_len);
-				r535_gsp_msg_dump(gsp, msg, NV_DBG_ERROR);
-				r535_gsp_msg_done(gsp, msg);
+				r535_gsp_msg_dump(gsp, rpc, NV_DBG_ERROR);
+				r535_gsp_msg_done(gsp, rpc);
 				return ERR_PTR(-EIO);
 			}
 
-			return msg;
+			return rpc;
 		}
 
-		r535_gsp_msg_done(gsp, msg);
+		r535_gsp_msg_done(gsp, rpc);
 		return NULL;
 	}
 
 	for (i = 0; i < gsp->msgq.ntfy_nr; i++) {
 		struct nvkm_gsp_msgq_ntfy *ntfy = &gsp->msgq.ntfy[i];
 
-		if (ntfy->fn == msg->function) {
+		if (ntfy->fn == rpc->function) {
 			if (ntfy->func)
-				ntfy->func(ntfy->priv, ntfy->fn, msg->data, msg->length -
sizeof(*msg));
+				ntfy->func(ntfy->priv, ntfy->fn, rpc->data,
+					   rpc->length - sizeof(*rpc));
 			break;
 		}
 	}
 
 	if (i == gsp->msgq.ntfy_nr)
-		r535_gsp_msg_dump(gsp, msg, NV_DBG_WARN);
+		r535_gsp_msg_dump(gsp, rpc, NV_DBG_WARN);
 
-	r535_gsp_msg_done(gsp, msg);
+	r535_gsp_msg_done(gsp, rpc);
 	if (fn)
 		goto retry;
 
-- 
2.34.1

On Thu, 2024-10-31 at 01:52 -0700, Zhi Wang wrote:
> @@ -336,59 +336,60 @@ static struct nvfw_gsp_rpc *
> ?r535_gsp_msg_recv(struct nvkm_gsp *gsp, int fn, u32 gsp_rpc_len)
> ?{
> ?	struct nvkm_subdev *subdev = &gsp->subdev;
> -	struct nvfw_gsp_rpc *msg;
> +	struct nvfw_gsp_rpc *rpc;
> ?	int time = 4000000, i;
> ?	u32 size;
> ?
> ?retry:
> -	msg = r535_gsp_msgq_wait(gsp, sizeof(*msg), &size, &time);
> -	if (IS_ERR_OR_NULL(msg))
> -		return msg;
> +	rpc = r535_gsp_msgq_wait(gsp, sizeof(*rpc), &size, &time);
> +	if (IS_ERR_OR_NULL(rpc))
> +		return rpc;
I know this change is supposed to be non-functional, but I did notice a
pattern here.

This function:

	rpc = r535_gsp_msgq_wait(gsp, sizeof(*rpc), &size, &time);
	if (IS_ERR_OR_NULL(rpc))
		return rpc;

Function r535_gsp_rpc_poll, which calls this function:

	repv = r535_gsp_msg_recv(gsp, fn, 0);
	mutex_unlock(&gsp->cmdq.mutex);
	if (IS_ERR(repv))
		return PTR_ERR(repv);

So if rpc is NULL, r535_gsp_msg_recv() will return NULL, but r535_gsp_rpc_poll
expects an error code instead.  Since it technically doesn't get one, it
returns 0 (success).

To be fair, it does not appear that r535_gsp_msgq_wait() can return NULL, but
that is obscured by the code.