[PATCH 2/3] HID: valve-index: Reboot headset on system power transitions

@@ -0,0 +1,12 @@
+What:		/sys/bus/hid/devices/<bus>:<vid>:<pid>.<n>/reboot
+Date:		October 2026
+Contact:	linux-input@vger.kernel.org
+Description:
+		Writing a boolean true value reboots the Valve Index headset to
+		recover its EDID service. Writing a boolean false value has no
+		effect. This file is write-only.
+
+		The Valve Index is a composite HID device. The reboot command is
+		only supported by the interface that provides the headset's 64-byte
+		output report. Writing true to this file on another interface fails
+		with -ENODEV.

@@ -547,6 +547,17 @@ config HID_WALTOP
 	help
 	Support for Waltop tablets.
 
+config HID_VALVE_INDEX
+	tristate "Valve Index headset"
+	depends on USB_HID
+	help
+	  Support for the Valve Index headset. This driver works around the
+	  headset failing to provide its EDID after a DisplayPort link shutdown
+	  by rebooting the headset on resume from system suspend and at shutdown.
+
+	  To compile this driver as a module, choose M here: the module will be
+	  called hid-valve-index.
+
 config HID_VIEWSONIC
 	tristate "ViewSonic/Signotec"
 	help

@@ -156,6 +156,7 @@ obj-$(CONFIG_HID_XIAOMI)	+= hid-xiaomi.o
 obj-$(CONFIG_HID_XINMO)		+= hid-xinmo.o
 obj-$(CONFIG_HID_ZEROPLUS)	+= hid-zpff.o
 obj-$(CONFIG_HID_ZYDACRON)	+= hid-zydacron.o
+obj-$(CONFIG_HID_VALVE_INDEX)	+= hid-valve-index.o
 obj-$(CONFIG_HID_VIEWSONIC)	+= hid-viewsonic.o
 obj-$(CONFIG_HID_VRC2)		+= hid-vrc2.o
 obj-$(CONFIG_HID_HUAWEI)	+= hid-huawei.o

@@ -1391,6 +1391,7 @@
 #define USB_DEVICE_ID_STEAM_CONTROLLER_IBEX_BLE	0x1303
 #define USB_DEVICE_ID_STEAM_CONTROLLER_PROTEUS	0x1304
 #define USB_DEVICE_ID_STEAM_CONTROLLER_NEREID	0x1305
+#define USB_DEVICE_ID_VALVE_INDEX_HEADSET	0x2300
 
 #define USB_VENDOR_ID_STEELSERIES	0x1038
 #define USB_DEVICE_ID_STEELSERIES_SRWS1	0x1410

@@ -0,0 +1,142 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * HID driver for the Valve Index headset
+ */
+
+#include <linux/hid.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define VALVE_INDEX_REBOOT_REPORT_ID	0x16
+#define VALVE_INDEX_REBOOT_CMD		0x01
+#define VALVE_INDEX_REPORT_SIZE		64
+
+static bool valve_index_has_reboot_report(struct hid_device *hdev)
+{
+	struct hid_report *report;
+
+	/*
+	 * The reboot command is a vendor protocol carried in the unnumbered
+	 * 64-byte output report of the headset's third interface; the first
+	 * data byte is the command id.  Report 0x16 is only declared as a
+	 * feature report and is not what the command is sent as.
+	 */
+	report = hdev->report_enum[HID_OUTPUT_REPORT].report_id_hash[0];
+
+	return report && hid_report_len(report) == VALVE_INDEX_REPORT_SIZE;
+}
+
+static void valve_index_reboot(struct hid_device *hdev, bool wake)
+{
+	u8 *report;
+	int ret;
+
+	if (!valve_index_has_reboot_report(hdev))
+		return;
+
+	/* USB transfer buffers must be DMA-able, so not on the stack. */
+	report = kzalloc(VALVE_INDEX_REPORT_SIZE, GFP_KERNEL);
+	if (!report)
+		return;
+	report[0] = VALVE_INDEX_REBOOT_REPORT_ID;
+	report[1] = VALVE_INDEX_REBOOT_CMD;
+
+	if (wake) {
+		ret = hid_hw_power(hdev, PM_HINT_FULLON);
+		if (ret < 0) {
+			hid_warn(hdev, "failed to resume headset for reboot: %d\n",
+				 ret);
+			goto out;
+		}
+	}
+
+	/* Use the same interrupt-out then SET_REPORT fallback as hidraw. */
+	ret = hid_hw_output_report(hdev, report, VALVE_INDEX_REPORT_SIZE);
+	if (ret == -ENOSYS)
+		ret = hid_hw_raw_request(hdev, report[0], report,
+					 VALVE_INDEX_REPORT_SIZE,
+					 HID_OUTPUT_REPORT, HID_REQ_SET_REPORT);
+	if (ret < 0)
+		hid_warn(hdev, "failed to reboot headset: %d\n", ret);
+	else if (ret != VALVE_INDEX_REPORT_SIZE)
+		hid_warn(hdev, "short headset reboot report: %d\n", ret);
+
+	if (wake)
+		hid_hw_power(hdev, PM_HINT_NORMAL);
+out:
+	kfree(report);
+}
+
+/*
+ * The suspend and shutdown hooks only cover orderly power transitions.  After
+ * a crash, a hard reset or a power cut the headset is left in the state where
+ * its EDID no longer reads, and nothing recovers it until the next orderly
+ * transition.  Expose the reboot command as a write-only "reboot" attribute
+ * on the HID device so userspace can recover it, for instance from a udev
+ * rule that fires only when the connector reports no EDID.  Writing to an
+ * interface that does not carry the reboot report returns -ENODEV.
+ */
+static ssize_t reboot_store(struct device *dev, struct device_attribute *attr,
+			    const char *buf, size_t count)
+{
+	struct hid_device *hdev = to_hid_device(dev);
+	bool val;
+
+	if (kstrtobool(buf, &val))
+		return -EINVAL;
+	if (!val)
+		return count;
+	if (!valve_index_has_reboot_report(hdev))
+		return -ENODEV;
+
+	valve_index_reboot(hdev, true);
+
+	return count;
+}
+static DEVICE_ATTR_WO(reboot);
+
+static struct attribute *valve_index_attrs[] = {
+	&dev_attr_reboot.attr,
+	NULL
+};
+ATTRIBUTE_GROUPS(valve_index);
+
+/*
+ * The headset's EDID service is lost when the host disables the DisplayPort
+ * PHY during system suspend, so it needs the reboot on the way out of
+ * suspend.  Doing it on the way in does not work: the headset dropping off
+ * USB is a remote-wakeup event from its hub and aborts the suspend.
+ */
+static int valve_index_resume(struct hid_device *hdev)
+{
+	valve_index_reboot(hdev, false);
+
+	return 0;
+}
+
+static void valve_index_shutdown(struct hid_device *hdev)
+{
+	valve_index_reboot(hdev, true);
+}
+
+static const struct hid_device_id valve_index_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_VALVE,
+			 USB_DEVICE_ID_VALVE_INDEX_HEADSET) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, valve_index_devices);
+
+static struct hid_driver valve_index_driver = {
+	.name = "valve-index",
+	.id_table = valve_index_devices,
+	.resume = valve_index_resume,
+	.reset_resume = valve_index_resume,
+	.shutdown = valve_index_shutdown,
+	.driver.dev_groups = valve_index_groups,
+};
+module_hid_driver(valve_index_driver);
+
+MODULE_AUTHOR("Mario Limonciello <mario.limonciello@amd.com>");
+MODULE_DESCRIPTION("HID driver for Valve Index headset");
+MODULE_LICENSE("GPL");