From 1e839143d674603b0bbbc4c513bca35404967dbc Mon Sep 17 00:00:00 2001 From: Benjamin Tissoires Date: Fri, 2 Sep 2022 15:29:23 +0200 Subject: [PATCH] HID: core: store the unique system identifier in hid_device This unique identifier is currently used only for ensuring uniqueness in sysfs. However, this could be handful for userspace to refer to a specific hid_device by this id. 2 use cases are in my mind: LEDs (and their naming convention), and HID-BPF. Reviewed-by: Greg Kroah-Hartman Signed-off-by: Benjamin Tissoires Link: https://lore.kernel.org/r/20220902132938.2409206-9-benjamin.tissoires@redhat.com --- drivers/hid/hid-core.c | 4 +++- include/linux/hid.h | 2 ++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index b7f5566e338d7..a00dd43db8bff 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2739,10 +2739,12 @@ int hid_add_device(struct hid_device *hdev) hid_warn(hdev, "bad device descriptor (%d)\n", ret); } + hdev->id = atomic_inc_return(&id); + /* XXX hack, any other cleaner solution after the driver core * is converted to allow more than 20 bytes as the device name? */ dev_set_name(&hdev->dev, "%04X:%04X:%04X.%04X", hdev->bus, - hdev->vendor, hdev->product, atomic_inc_return(&id)); + hdev->vendor, hdev->product, hdev->id); hid_debug_register(hdev, dev_name(&hdev->dev)); ret = device_add(&hdev->dev); diff --git a/include/linux/hid.h b/include/linux/hid.h index 4363a63b9775e..a43dd17bc78fd 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -658,6 +658,8 @@ struct hid_device { /* device report descriptor */ struct list_head debug_list; spinlock_t debug_list_lock; wait_queue_head_t debug_wait; + + unsigned int id; /* system unique id */ }; #define to_hid_device(pdev) \ -- 2.30.2