diff --git a/drivers/mailbox/pcc.c b/drivers/mailbox/pcc.c
index 3ef7f036ceea..cc77a2f1694f 100644
--- a/drivers/mailbox/pcc.c
+++ b/drivers/mailbox/pcc.c
@@ -372,6 +372,35 @@ static const struct mbox_chan_ops pcc_chan_ops = {
 	.send_data = pcc_send_data,
 };
 
+/*
+ *
+ * count_pcc_subspaces -- Count the PCC subspaces that are not used in
+ *		reduced hardware systems.
+ * @header: Pointer to the ACPI subtable header under the PCCT.
+ * @end: End of subtable entry.
+ *
+ * Return: 0 for Success, else errno.
+ *
+ * This gets called for each entry in the PCC table.
+ */
+static int count_pcc_subspaces(struct acpi_subtable_header *header,
+		const unsigned long end)
+{
+	struct acpi_pcct_subspace *pcct_ss =
+				(struct acpi_pcct_subspace *) header;
+
+	if ((pcct_ss->header.type <= ACPI_PCCT_TYPE_RESERVED) &&
+	    (pcct_ss->header.type != ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE) &&
+	    (pcct_ss->header.type !=
+				ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
+		pr_warn("PCCT count: useful subtype = %d\n",
+			pcct_ss->header.type);
+		return 0;
+	}
+	pr_warn("PCCT count: unwanted subtype = %d\n", pcct_ss->header.type);
+	return -EINVAL;
+}
+
 /**
  * parse_pcc_subspace - Parse the PCC table and verify PCC subspace
  *		entries. There should be one entry per PCC client.
@@ -395,10 +424,14 @@ static int parse_pcc_subspace(struct acpi_subtable_header *header,
 		    && (pcct_ss->header.type !=
 				ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)) {
 			pr_err("Incorrect PCC Subspace type detected\n");
+			pr_warn("PCCT parse: unwanted subtype = %d\n",
+				pcct_ss->header.type);
 			return -EINVAL;
 		}
 	}
 
+	pcct_ss = (struct acpi_pcct_hw_reduced *) header;
+	pr_warn("PCCT parse: useful subtype = %d\n", pcct_ss->header.type);
 	return 0;
 }
 
@@ -449,8 +482,8 @@ static int __init acpi_pcc_probe(void)
 	struct acpi_table_header *pcct_tbl;
 	struct acpi_subtable_header *pcct_entry;
 	struct acpi_table_pcct *acpi_pcct_tbl;
+	struct acpi_subtable_proc proc[ACPI_PCCT_TYPE_RESERVED];
 	int count, i, rc;
-	int sum = 0;
 	acpi_status status = AE_OK;
 
 	/* Search for PCCT */
@@ -459,43 +492,50 @@ static int __init acpi_pcc_probe(void)
 	if (ACPI_FAILURE(status) || !pcct_tbl)
 		return -ENODEV;
 
-	count = acpi_table_parse_entries(ACPI_SIG_PCCT,
-			sizeof(struct acpi_table_pcct),
-			ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE,
-			parse_pcc_subspace, MAX_PCC_SUBSPACES);
-	sum += (count > 0) ? count : 0;
-
-	count = acpi_table_parse_entries(ACPI_SIG_PCCT,
-			sizeof(struct acpi_table_pcct),
-			ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2,
-			parse_pcc_subspace, MAX_PCC_SUBSPACES);
-	sum += (count > 0) ? count : 0;
+	/* Set up the subtable handlers */
+	for (i = ACPI_PCCT_TYPE_GENERIC_SUBSPACE;
+	     i < ACPI_PCCT_TYPE_RESERVED;
+	     i++) {
+		proc[i].id = i;
+		if (i == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
+		    i == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2)
+			proc[i].handler = parse_pcc_subspace;
+		else
+			proc[i].handler = count_pcc_subspaces;
+		proc[i].count = 0;
+	}
 
-	if (sum == 0 || sum >= MAX_PCC_SUBSPACES) {
-		pr_err("Error parsing PCC subspaces from PCCT\n");
+	count = acpi_table_parse_entries_array(ACPI_SIG_PCCT,
+			sizeof(struct acpi_table_pcct), proc,
+			ACPI_PCCT_TYPE_RESERVED, MAX_PCC_SUBSPACES);
+	if (count == 0) {
+		pr_warn("PCCT provided but has no subspaces defined\n");
+		return -EINVAL;
+	} else if (count > MAX_PCC_SUBSPACES) {
+		pr_warn("Too many PCC subspaces defined in PCCT\n");
 		return -EINVAL;
 	}
 
 	pcc_mbox_channels = kzalloc(sizeof(struct mbox_chan) *
-			sum, GFP_KERNEL);
+			count, GFP_KERNEL);
 	if (!pcc_mbox_channels) {
 		pr_err("Could not allocate space for PCC mbox channels\n");
 		return -ENOMEM;
 	}
 
-	pcc_doorbell_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
+	pcc_doorbell_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
 	if (!pcc_doorbell_vaddr) {
 		rc = -ENOMEM;
 		goto err_free_mbox;
 	}
 
-	pcc_doorbell_ack_vaddr = kcalloc(sum, sizeof(void *), GFP_KERNEL);
+	pcc_doorbell_ack_vaddr = kcalloc(count, sizeof(void *), GFP_KERNEL);
 	if (!pcc_doorbell_ack_vaddr) {
 		rc = -ENOMEM;
 		goto err_free_db_vaddr;
 	}
 
-	pcc_doorbell_irq = kcalloc(sum, sizeof(int), GFP_KERNEL);
+	pcc_doorbell_irq = kcalloc(count, sizeof(int), GFP_KERNEL);
 	if (!pcc_doorbell_irq) {
 		rc = -ENOMEM;
 		goto err_free_db_ack_vaddr;
@@ -509,18 +549,25 @@ static int __init acpi_pcc_probe(void)
 	if (acpi_pcct_tbl->flags & ACPI_PCCT_DOORBELL)
 		pcc_mbox_ctrl.txdone_irq = true;
 
-	for (i = 0; i < sum; i++) {
+	for (i = 0; i < count; i++) {
 		struct acpi_generic_address *db_reg;
-		struct acpi_pcct_hw_reduced *pcct_ss;
+		struct acpi_pcct_subspace *pcct_ss;
 		pcc_mbox_channels[i].con_priv = pcct_entry;
 
-		pcct_ss = (struct acpi_pcct_hw_reduced *) pcct_entry;
+		if (pcct_entry->type == ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE ||
+		    pcct_entry->type ==
+				ACPI_PCCT_TYPE_HW_REDUCED_SUBSPACE_TYPE2) {
+			struct acpi_pcct_hw_reduced *pcct_hrss;
+
+			pcct_hrss = (struct acpi_pcct_hw_reduced *) pcct_entry;
 
-		if (pcc_mbox_ctrl.txdone_irq) {
-			rc = pcc_parse_subspace_irq(i, pcct_ss);
-			if (rc < 0)
-				goto err;
+			if (pcc_mbox_ctrl.txdone_irq) {
+				rc = pcc_parse_subspace_irq(i, pcct_hrss);
+				if (rc < 0)
+					goto err;
+			}
 		}
+		pcct_ss = (struct acpi_pcct_subspace *) pcct_entry;
 
 		/* If doorbell is in system memory cache the virt address */
 		db_reg = &pcct_ss->doorbell_register;
@@ -531,7 +578,7 @@ static int __init acpi_pcc_probe(void)
 			((unsigned long) pcct_entry + pcct_entry->length);
 	}
 
-	pcc_mbox_ctrl.num_chans = sum;
+	pcc_mbox_ctrl.num_chans = count;
 
 	pr_info("Detected %d PCC Subspaces\n", pcc_mbox_ctrl.num_chans);
 
