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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 v2 1/5] platform/x86/intel/tpmi: Don't create devices for disabled features
Date:   Thu, 30 Nov 2023 13:47:47 -0800
Message-Id: <20231130214751.3100418-2-srinivas.pandruvada@linux.intel.com>
In-Reply-To: <20231130214751.3100418-1-srinivas.pandruvada@linux.intel.com>
References: <20231130214751.3100418-1-srinivas.pandruvada@linux.intel.com>
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If some TPMI features are disabled, don't create auxiliary devices. In
this way feature drivers will not load.

While creating auxiliary devices, call tpmi_read_feature_status() to
check feature state and return if the feature is disabled without
creating a device.

Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
---
v2
- Add comment for returning -EOPNOTSUPP

 drivers/platform/x86/intel/tpmi.c | 14 +++++++++++++-
 1 file changed, 13 insertions(+), 1 deletion(-)

diff --git a/drivers/platform/x86/intel/tpmi.c b/drivers/platform/x86/intel/tpmi.c
index c89aa4d14bea..868067ff966e 100644
--- a/drivers/platform/x86/intel/tpmi.c
+++ b/drivers/platform/x86/intel/tpmi.c
@@ -604,9 +604,21 @@ static int tpmi_create_device(struct intel_tpmi_info *tpmi_info,
 	struct intel_vsec_device *vsec_dev = tpmi_info->vsec_dev;
 	char feature_id_name[TPMI_FEATURE_NAME_LEN];
 	struct intel_vsec_device *feature_vsec_dev;
+	struct tpmi_feature_state feature_state;
 	struct resource *res, *tmp;
 	const char *name;
-	int i;
+	int i, ret;
+
+	ret = tpmi_read_feature_status(tpmi_info, pfs->pfs_header.tpmi_id, &feature_state);
+	if (ret)
+		return ret;
+
+	/*
+	 * If not enabled, continue to look at other features in the PFS, so return -EOPNOTSUPP.
+	 * This will not cause failure of loading of this driver.
+	 */
+	if (!feature_state.enabled)
+		return -EOPNOTSUPP;
 
 	name = intel_tpmi_name(pfs->pfs_header.tpmi_id);
 	if (!name)
-- 
2.41.0