From ef195e8a7f43924b9979b2cd81ac7fa54f24bb3c Mon Sep 17 00:00:00 2001
From: "David E. Box" <david.e.box@linux.intel.com>
Date: Tue, 17 Aug 2021 15:40:17 -0700
Subject: [PATCH] platform/x86: intel_pmt_telemetry: Ignore zero sized entries
Git-commit: ef195e8a7f43924b9979b2cd81ac7fa54f24bb3c
Patch-mainline: v5.15-rc1
References: bsc#1196591

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.com
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 drivers/platform/x86/intel/pmt/telemetry.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/platform/x86/intel/pmt/telemetry.c b/drivers/platform/x86/intel/pmt/telemetry.c
index a58843360fbf..38d52651c572 100644
--- a/drivers/platform/x86/intel/pmt/telemetry.c
+++ b/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;
 }
 
-- 
2.31.1