vgsp: eng64 - chain the release behind the pack carrier and name a stalled carrier's gate

c779: the pack-continuation carrier completed the pack
(MME-CARRY-COMPLETE gen=4 off=2799/2799) and armed the release
(MME-CARRY-ARM mode=release), but its launch poll held the single
forwarding slot for 2801 ms; the armed release then deferred
request-inflight until the beef channel unregistered at +2.2 s, so the
release ended in MME-CARRY-HOLD reason=no-channel.

- svc_fwd_gr_work: after a successful synthetic pack carrier, wait out
  the release grace in the same slot, claim it and run the release work
  directly (chained MME-CARRY-FIRE mode=release ... receipt). Gate:
  sema_gl_mme_release_chain (default 1; release carrier still default 0).
- pump pack-carry block: an armed due carrier that cannot go out now
  names its blocker (MME-CARRY-WAIT reason=no-channel/client-candidate/
  request-inflight/fe-defer), so the c781-class silent stall is visible.
- booter: gsp_phys_gr_mme_release_waiting()/chain_enabled() helpers.

c783-c785 (a03a68ea build) were all shallow (author=0, no MME window).

1 files changed, 35 insertions, 0 deletions

diff --git a/kernel/gsp_phys_booter.c b/kernel/gsp_phys_booter.c
index 4cf1c55..74b0300 100644
--- a/kernel/gsp_phys_booter.c
+++ b/kernel/gsp_phys_booter.c
@@ -19011,6 +19011,23 @@ MODULE_PARM_DESC(sema_gl_mme_release_sa_arm,
 	"Re-emit the START-ADDRESS RAM pairs (incl. golden slot 34 -> IR 0x265) before a saved-window release launch so CALL_MME_MACRO(34) resolves to DRAW_IAB (default 0; needs sema_gl_mme_pack_release=1)");
 
 /*
+ * Release chaining (sema_gl_mme_release_chain): the host pack-continuation
+ * carrier's launch poll owns the single forwarding slot for up to
+ * sema_mme_fast_ms (c779 elapsed 2801 ms), and the client's 3D channel can
+ * unregister before the next service pass fires the armed release (c779:
+ * release ARM at +0.1 s, beef channel unregistered ~2.2 s later ->
+ * MME-CARRY-HOLD reason=no-channel). With this on, a successful synthetic
+ * pack carrier claims the armed release after its settle grace and runs the
+ * release work in the same slot, while the channel is still alive. Default 1;
+ * the release carrier itself is default off.
+ */
+static bool gsp_phys_rmcall_gr_mme_release_chain = true;
+module_param_named(sema_gl_mme_release_chain,
+		   gsp_phys_rmcall_gr_mme_release_chain, bool, 0644);
+MODULE_PARM_DESC(sema_gl_mme_release_chain,
+	"Run the armed saved-window release in the same forwarding slot right after a successful host pack-continuation carrier (default 1; needs sema_gl_mme_pack_release=1)");
+
+/*
  * DRAW_IAB preference (release carrier follow-up): the held-call window that
  * matters is the DRAW window, whose method stream carries the
  * CALL_MME_MACRO(34) run that expands to DRAW_IAB (mac=0x22).
@@ -19470,6 +19487,24 @@ bool gsp_phys_gr_mme_release_take(u32 h_object, u32 *held, u32 *win)
 	return true;
 }
 
+/* An armed release is still owed (before its grace deadline too). */
+bool gsp_phys_gr_mme_release_waiting(void)
+{
+	struct gsp_phys_gr_mme_release_state *s = &gsp_phys_gr_mme_release;
+	unsigned long flags;
+	bool waiting;
+
+	spin_lock_irqsave(&gsp_phys_gr_mme_release_lock, flags);
+	waiting = s->valid && s->armed && !s->fired && !s->consumed;
+	spin_unlock_irqrestore(&gsp_phys_gr_mme_release_lock, flags);
+	return waiting;
+}
+
+bool gsp_phys_gr_mme_release_chain_enabled(void)
+{
+	return READ_ONCE(gsp_phys_rmcall_gr_mme_release_chain);
+}
+
 /* The release is still claimed and not cancelled (builder safety gate). */
 static bool gsp_phys_gr_mme_release_active(void)
 {