[Skiboot] [PATCH] opal/fsp: Fix opal boot failure on systems with redundant FSP

[Reza Arbab]

On Mon, Mar 17, 2025 at 09:30:03AM +0530, Mahesh Salgaonkar wrote:
>--- a/hw/fsp/fsp.c
>+++ b/hw/fsp/fsp.c
>@@ -76,6 +76,7 @@ struct fsp {
> 	unsigned int		iopath_count;
> 	int			active_iopath;	/* -1: no active IO path */
> 	struct fsp_iopath	iopath[FSP_MAX_IOPATH];
>+	bool			primary;
> };
>
> enum ipl_state {
>@@ -1959,7 +1960,7 @@ static void fsp_update_links_states(struct fsp *fsp)
> 	}
>
> 	if (fsp->active_iopath >= 0) {
>-		if (!active_fsp || (active_fsp != fsp))
>+		if (active_fsp && (active_fsp != fsp))
> 			active_fsp = fsp;

What happens if none of the fsp nodes in the device tree has the 
"primary" property? With this change, won't active_fsp stay NULL 
forever? Maybe the above line should just be

		if (active_fsp != fsp)

or even remove the conditional completely and just always do the 
assignment?

>
> 		fsp_inbound_off = 0;
>@@ -2003,8 +2004,12 @@ static void fsp_create_fsp(struct dt_node 
>*fsp_node)
> 	fsp->index = index;
> 	fsp->active_iopath = -1;
>
>+	if (dt_find_property(fsp_node, "primary"))
>+		fsp->primary = true;
>+
> 	count = linksprop->len / 4;
>-	prlog(PR_DEBUG, "FSP #%d: Found %d IO PATH\n", index, count);
>+	prlog(PR_DEBUG, "FSP #%d: Found %d IO PATH %s\n", index, count,
>+			fsp->primary ? "(Primary FSP)" : "");
> 	if (count > FSP_MAX_IOPATH) {
> 		prerror("FSP #%d: WARNING, limited to %d IO PATH\n",
> 			index, FSP_MAX_IOPATH);
>@@ -2073,6 +2078,16 @@ int fsp_fatal_msg(struct fsp_msg *msg)
> 	return rc;
> }
>
>+static void fsp_init_set_active(void)
>+{
>+	struct fsp *fsp;
>+
>+	/* Mark primary FSP as active fsp during boot */
>+	for (fsp = first_fsp; fsp; fsp = fsp->link)
>+		if (fsp->primary)
>+			active_fsp = fsp;
>+}
>+
> static bool fsp_init_one(const char *compat)
> {
> 	struct dt_node *fsp_node;
>@@ -2104,6 +2119,7 @@ static bool fsp_init_one(const char *compat)
> 		/* Create the FSP data structure */
> 		fsp_create_fsp(fsp_node);
> 	}
>+	fsp_init_set_active();
>
> 	return inited;
> }

-- 
Reza Arbab