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From:   Akihiko Odaki <akihiko.odaki@gmail.com>
Cc:     Basavaraj Natikar <basavaraj.natikar@amd.com>,
        Jiri Kosina <jikos@kernel.org>,
        Benjamin Tissoires <benjamin.tissoires@redhat.com>,
        linux-input@vger.kernel.org, linux-kernel@vger.kernel.org,
        Akihiko Odaki <akihiko.odaki@gmail.com>,
        Mario Limonciello <mario.limonciello@amd.com>
Subject: [PATCH v3] AMD_SFH: Add a DMI quirk entry for Chromebooks
Date:   Tue, 16 Aug 2022 19:21:20 +0900
Message-Id: <20220816102120.6131-1-akihiko.odaki@gmail.com>
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Precedence: bulk

Google Chromebooks use Chrome OS Embedded Controller Sensor Hub instead
of Sensor Hub Fusion and leaves MP2 uninitialized, which disables all
functionalities, even including the registers necessary for feature
detections.

The behavior was observed with Lenovo ThinkPad C13 Yoga.

Signed-off-by: Akihiko Odaki <akihiko.odaki@gmail.com>
Suggested-by: Mario Limonciello <mario.limonciello@amd.com>
---
 drivers/hid/amd-sfh-hid/amd_sfh_pcie.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
index 4b90c86ee5f8..47774b9ab3de 100644
--- a/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
+++ b/drivers/hid/amd-sfh-hid/amd_sfh_pcie.c
@@ -288,11 +288,29 @@ int amd_sfh_irq_init(struct amd_mp2_dev *privdata)
 	return 0;
 }
 
+static const struct dmi_system_id dmi_nodevs[] = {
+	{
+		/*
+		 * Google Chromebooks use Chrome OS Embedded Controller Sensor
+		 * Hub instead of Sensor Hub Fusion and leaves MP2
+		 * uninitialized, which disables all functionalities, even
+		 * including the registers necessary for feature detections.
+		 */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "Google"),
+		},
+	},
+	{ }
+};
+
 static int amd_mp2_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 {
 	struct amd_mp2_dev *privdata;
 	int rc;
 
+	if (dmi_first_match(dmi_nodevs))
+		return -ENODEV;
+
 	privdata = devm_kzalloc(&pdev->dev, sizeof(*privdata), GFP_KERNEL);
 	if (!privdata)
 		return -ENOMEM;
-- 
2.37.2