From: Mario Limonciello Date: Tue, 10 Mar 2026 07:29:27 +0000 (+0000) Subject: HID: Include firmware version in the uevent X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=6ca9029c823b7853e980585e757343e0e84227cd;p=thirdparty%2Fkernel%2Flinux.git HID: Include firmware version in the uevent Userspace software fwupd probes some HID devices when the daemon starts up to determine the current firmware version in order to be able to offer updated firmware if the manufacturer has made it available. In order to do this fwupd will detach the existing kernel driver if one is present, send a HID command and then reattach the kernel driver. This can be problematic if the user is using the HID device at the time that fwupd probes the hardware and can cause a few frames of input to be dropped. In some cases HID drivers already have a command to look up the firmware version, and so if that is exported to userspace fwupd can discover it and avoid needing to detach the kernel driver until it's time to update the device. Introduce a new member in the struct hid_device for the version and export a new uevent variable HID_FIRMWARE_VERSION that will display the version that HID drivers obtained. Reviewed-by: Derek J. Clark Reviewed-by: Mark Pearson Cc: Richard Hughes Signed-off-by: Mario Limonciello Signed-off-by: Jiri Kosina --- diff --git a/drivers/hid/hid-core.c b/drivers/hid/hid-core.c index 840a601138688..da57cbf0af26d 100644 --- a/drivers/hid/hid-core.c +++ b/drivers/hid/hid-core.c @@ -2887,6 +2887,11 @@ static int hid_uevent(const struct device *dev, struct kobj_uevent_env *env) if (add_uevent_var(env, "MODALIAS=hid:b%04Xg%04Xv%08Xp%08X", hdev->bus, hdev->group, hdev->vendor, hdev->product)) return -ENOMEM; + if (hdev->firmware_version) { + if (add_uevent_var(env, "HID_FIRMWARE_VERSION=0x%04llX", + hdev->firmware_version)) + return -ENOMEM; + } return 0; } diff --git a/include/linux/hid.h b/include/linux/hid.h index 2990b9f94cb57..b0b70c05049df 100644 --- a/include/linux/hid.h +++ b/include/linux/hid.h @@ -698,6 +698,7 @@ struct hid_device { char name[128]; /* Device name */ char phys[64]; /* Device physical location */ char uniq[64]; /* Device unique identifier (serial #) */ + u64 firmware_version; /* Firmware version */ void *driver_data;