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From:   "David E. Box" <david.e.box@linux.intel.com>
To:     lee.jones@linaro.org, hdegoede@redhat.com, mgross@linux.intel.com,
        bhelgaas@google.com, srinivas.pandruvada@intel.com,
        andy.shevchenko@gmail.com
Cc:     "David E. Box" <david.e.box@linux.intel.com>,
        linux-kernel@vger.kernel.org, platform-driver-x86@vger.kernel.org,
        linux-pci@vger.kernel.org
Subject: [PATCH v2 4/5] platform/x86: intel_pmt_telemetry: Ignore zero sized entries
Date:   Tue, 17 Aug 2021 15:40:17 -0700
Message-Id: <20210817224018.1013192-5-david.e.box@linux.intel.com>
In-Reply-To: <20210817224018.1013192-1-david.e.box@linux.intel.com>
References: <20210817224018.1013192-1-david.e.box@linux.intel.com>
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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>
---

V2:	New patch

 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 3559f6e7b388..d93d02672679 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;
 }
 
-- 
2.25.1