diff --git a/src/include/sof/lib/ams.h b/src/include/sof/lib/ams.h
index 8cb3ae217400..e43d6208f875 100644
--- a/src/include/sof/lib/ams.h
+++ b/src/include/sof/lib/ams.h
@@ -29,10 +29,6 @@
 /* Space allocated for async message content*/
 #define AMS_MAX_MSG_SIZE 0x1000
 
-/* Size of slots message, module id and instance id */
-#define AMS_SLOT_SIZE(msg) (AMS_MESSAGE_SIZE(msg) + sizeof(uint16_t) * 2)
-#define AMS_MESSAGE_SIZE(msg) (sizeof(*msg) - sizeof(char) + (sizeof(char) * (msg->message_length)))
-
 /**
  * \brief IXC message payload
  *
diff --git a/src/lib/ams.c b/src/lib/ams.c
index 31bca13ce833..b1752976e0c5 100644
--- a/src/lib/ams.c
+++ b/src/lib/ams.c
@@ -285,9 +285,13 @@ static uint32_t ams_push_slot(struct ams_shared_context __sparse_cache *ctx_shar
 
 	for (uint32_t i = 0; i < ARRAY_SIZE(ctx_shared->slots); ++i) {
 		if (ctx_shared->slot_uses[i] == 0) {
+			/* the slot only carries the payload struct (read back
+			 * via u.msg); message points to a caller-owned buffer
+			 * rather than inline data, so copy exactly the struct
+			 */
 			err = memcpy_s((__sparse_force void *)ctx_shared->slots[i].u.msg_raw,
 				       sizeof(ctx_shared->slots[i].u.msg_raw),
-				       msg, AMS_MESSAGE_SIZE(msg));
+				       msg, sizeof(*msg));
 
 			if (err != 0)
 				return AMS_INVALID_SLOT;
diff --git a/src/lib/cpu-clk-manager.c b/src/lib/cpu-clk-manager.c
index 59744063e4b9..df917fab4f9d 100644
--- a/src/lib/cpu-clk-manager.c
+++ b/src/lib/cpu-clk-manager.c
@@ -28,6 +28,13 @@ static int request_freq_change(unsigned int core, int freq)
 			break;
 	}
 
+	/* if no entry was larger than the requested frequency the loop ends with
+	 * selected_freq_id == clk->freqs_num; clamp to the last valid entry
+	 * before indexing
+	 */
+	if (selected_freq_id == clk->freqs_num)
+		selected_freq_id = clk->freqs_num - 1;
+
 	/* don't change clock frequency if already using proper clock */
 	current_freq = clock_get_freq(core);
 	if (clk->freqs[selected_freq_id].freq != current_freq)