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From:   Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
To:     hdegoede@redhat.com, markgross@kernel.org,
        ilpo.jarvinen@linux.intel.com, andriy.shevchenko@linux.intel.com
Cc:     platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Subject: [PATCH 2/3] platform/x86: ISST : Check major minor version
Date:   Mon, 25 Sep 2023 12:43:37 -0700
Message-Id: <20230925194338.966639-3-srinivas.pandruvada@linux.intel.com>
In-Reply-To: <20230925194338.966639-1-srinivas.pandruvada@linux.intel.com>
References: <20230925194338.966639-1-srinivas.pandruvada@linux.intel.com>
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Parse major and minor version number from the version field. If there
is a mismatch for major version, exit from further processing for that
domain.

If there is mismatch in minor version, driver continue to process with
an error message. Minor version change doesn't change offsets and bit
structures of TPMI fields.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
 .../x86/intel/speed_select_if/isst_tpmi_core.c   | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
index 63faa2ea8327..37f17e229419 100644
--- a/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
+++ b/drivers/platform/x86/intel/speed_select_if/isst_tpmi_core.c
@@ -30,7 +30,8 @@
 #include "isst_if_common.h"
 
 /* Supported SST hardware version by this driver */
-#define ISST_HEADER_VERSION		1
+#define ISST_MAJOR_VERSION	0
+#define ISST_MINOR_VERSION	1
 
 /*
  * Used to indicate if value read from MMIO needs to get multiplied
@@ -352,12 +353,19 @@ static int sst_main(struct auxiliary_device *auxdev, struct tpmi_per_power_domai
 	pd_info->sst_header.cp_offset *= 8;
 	pd_info->sst_header.pp_offset *= 8;
 
-	if (pd_info->sst_header.interface_version != ISST_HEADER_VERSION) {
-		dev_err(&auxdev->dev, "SST: Unsupported version:%x\n",
-			pd_info->sst_header.interface_version);
+	if (pd_info->sst_header.interface_version == TPMI_VERSION_INVALID)
+		return -ENODEV;
+
+	if (TPMI_MAJOR_VERSION(pd_info->sst_header.interface_version) != ISST_MAJOR_VERSION) {
+		dev_err(&auxdev->dev, "SST: Unsupported major version:%lx\n",
+			TPMI_MAJOR_VERSION(pd_info->sst_header.interface_version));
 		return -ENODEV;
 	}
 
+	if (TPMI_MINOR_VERSION(pd_info->sst_header.interface_version) != ISST_MINOR_VERSION)
+		dev_err(&auxdev->dev, "SST: Ignore: Unsupported minor version:%lx\n",
+			TPMI_MINOR_VERSION(pd_info->sst_header.interface_version));
+
 	/* Read SST CP Header */
 	*((u64 *)&pd_info->cp_header) = readq(pd_info->sst_base + pd_info->sst_header.cp_offset);
 
-- 
2.41.0