platform/x86: intel_pmt_telemetry: Ignore zero sized entries

Some devices may expose non-functioning entries that are reserved for
future use. These entries have zero size. Ignore them during probe.
Signed-off-by: David E. Box <david.e.box@linux.intel.com>
Link: https://lore.kernel.org/r/20210817224018.1013192-5-david.e.box@linux.intel.comReviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

drivers/platform/x86/intel/pmt/telemetry.c

@@ -61,6 +61,14 @@ static int pmt_telem_header_decode(struct intel_pmt_entry *entry,
 	/* Size is measured in DWORDS, but accessor returns bytes */
 	header->size = TELEM_SIZE(readl(disc_table));
 
+	/*
+	 * Some devices may expose non-functioning entries that are
+	 * reserved for future use. They have zero size. Do not fail
+	 * probe for these. Just ignore them.
+	 */
+	if (header->size == 0)
+		return 1;
+
 	return 0;
 }