From nobody Sat Feb 7 23:45:04 2026 Received: from mail-yw1-f201.google.com (mail-yw1-f201.google.com [209.85.128.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6A13263C7 for ; Thu, 7 Mar 2024 03:09:27 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709780968; cv=none; b=mCVnc2iac9g4QXmH+6KUeJfhlW0mKPcJJxJP4OY5WgdsRevIwbF0infU9LhYD7DinNjImuisdXlNY8QTnHDS9VjSKILgOzWw2xOrj+l0aOgzAA0BBfsDpfH8aqq4uvKxvRUdth3zTC4WqcXDWLJToEN8ejet297EIsYqmH0LTIk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709780968; c=relaxed/simple; bh=9VKCNfoO34uLb81d+s+T+24G9GZ1ZWMwJkSj0hyrqZY=; h=Date:Mime-Version:Message-ID:Subject:From:To:Content-Type; b=jcgON5eIp9t39tbz9qogtD+LjgYRZ5t+r/J7HlEcvH46+cyCKUQcEewIFsvd7FCtgeHgD3ujN+4HRzWobanptal0rR+bRHMBRBWZfS409HlzV8kGdAQ2Jm5/eRb3EUJu1ZlWc9JzLdS0UkHico9fpd+45C36fn/EjZNEk8iQXgM= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--royluo.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=uvsQp752; arc=none smtp.client-ip=209.85.128.201 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--royluo.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="uvsQp752" Received: by mail-yw1-f201.google.com with SMTP id 00721157ae682-609d8275c70so7372767b3.3 for ; Wed, 06 Mar 2024 19:09:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1709780966; x=1710385766; darn=vger.kernel.org; h=to:from:subject:message-id:mime-version:date:from:to:cc:subject :date:message-id:reply-to; bh=H5Ul/l6h3QQByB9upBvQ9wSmoGLdWz++Sa5jGQeBypo=; b=uvsQp752U+bq5zn6RGkp/M49d2MSATTBfqhBXMZdHv5v+NC1zVMNHmCTmZr/xbS3JX SeTUwNFLfN6FjSKEAfKwFycAH2qpCDzYWAjBpDEqARXIV3t+10auKnbUEQ6p2aFBvdqA nVmNQo6oIKdtbuMQcMeCARYhOch/UK3gKC+HfODRRbDa5x/PUOrRU5uAKakz7Z/6UiZN yvNw8tqq4w4xg7s2u6P2VoF8fog6CO8JF+/tY93iJVVvLgAhy+wRvUiFp9eYp5tbx4Hi 761onZY42phWeARNUQLWK1ZTeaPqHd2snlZPgSbwmmw6W74tgQDMKGqIa/5JZ7unlrLd i2cw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1709780966; x=1710385766; h=to:from:subject:message-id:mime-version:date:x-gm-message-state :from:to:cc:subject:date:message-id:reply-to; bh=H5Ul/l6h3QQByB9upBvQ9wSmoGLdWz++Sa5jGQeBypo=; b=m9xl45pCrE9LqsNQi5Fwmr/YJLLA9fw/2LV0It0FBuXHq9VVpYayDpvnVxlRMG0Pli t2YyWyqTbp/9lXpC1pDuzApnFsOGBKvk8ul2Xz21DKyur/ee7p8p13PgRyuUVyfKiaeS BctIFgbEYxPvMoRpf9GCaW1OvSKz4LJT2GVtGVOV/zKxCazsjv+aKCwfV5wZ2unp7MU6 mGkfTaXljnsm40VmXZpfHfW4J6pbLGuwBGwkXAig/bka8daWUi6sLFDKbxqUAxbzucsV 8BAlM+wXmvsC2X1zS95mRIDb/smLCTQPIfKflruhor1Pz5fFg4e8i0QBol9Glt4PpyX2 3cwg== X-Forwarded-Encrypted: i=1; AJvYcCXYKysghWURikCgxNqViS3sVE0MHKAkuu89arnlKoNPtzPXW4rhfipBl9XSjOJ8iEMwwEAKmpqtYHsdv3U3+67tJ3bzT3hkMaKBdMqU X-Gm-Message-State: AOJu0Yy4Vsq24l/h2PcjKoVCIuAYQDj8IajA2QVLREXdGISxb7hRLiAx ZnBeUh4wSHw4N1I4UK/7Hjx7w1CSk6IlqbyEs5GR6DSHoi+8PSxaAEoQV8pyG3JPBpGdTa3XhgR 0VA== X-Google-Smtp-Source: AGHT+IHeaYvtkY0Bcfb1Npr2PybT8dlXhavGfsAAIqzbqBoTOs8R7yumV2r/35rHceoTxqMk4lHGh/7MQQo= X-Received: from royluo-cloudtop0.c.googlers.com ([fda3:e722:ac3:cc00:14:4d90:c0a8:bb8]) (user=royluo job=sendgmr) by 2002:a05:690c:3612:b0:607:a30d:8cf with SMTP id ft18-20020a05690c361200b00607a30d08cfmr3779456ywb.4.1709780966471; Wed, 06 Mar 2024 19:09:26 -0800 (PST) Date: Thu, 7 Mar 2024 03:09:22 +0000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 X-Mailer: git-send-email 2.44.0.278.ge034bb2e1d-goog Message-ID: <20240307030922.3573161-1-royluo@google.com> Subject: [PATCH v1] USB: gadget: core: create sysfs link between udc and gadget From: Roy Luo To: royluo@google.com, gregkh@linuxfoundation.org, stern@rowland.harvard.edu, badhri@google.com, quic_kriskura@quicinc.com, francesco.dolcini@toradex.com, quic_eserrao@quicinc.com, ivan.orlov0322@gmail.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" udc device and gadget device are tightly coupled, yet there's no good way to corelate the two. Add a sysfs link in udc that points to the corresponding gadget device. An example use case: userspace configures a f_midi configfs driver and bind the udc device, then it tries to locate the corresponding midi device, which is a child device of the gadget device. The gadget device that's associated to the udc device has to be identified in order to index the midi device. Having a sysfs link would make things much easier. Signed-off-by: Roy Luo --- drivers/usb/gadget/udc/core.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index d59f94464b87..876b8635b16f 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -1419,8 +1419,16 @@ int usb_add_gadget(struct usb_gadget *gadget) if (ret) goto err_free_id; =20 + ret =3D sysfs_create_link(&udc->dev.kobj, + &gadget->dev.kobj, "gadget"); + if (ret) + goto err_del_gadget; + return 0; =20 + err_del_gadget: + device_del(&gadget->dev); + err_free_id: ida_free(&gadget_id_numbers, gadget->id_number); =20 @@ -1529,6 +1537,7 @@ void usb_del_gadget(struct usb_gadget *gadget) mutex_unlock(&udc_lock); =20 kobject_uevent(&udc->dev.kobj, KOBJ_REMOVE); + sysfs_remove_link(&udc->dev.kobj, "gadget"); flush_work(&gadget->work); device_del(&gadget->dev); ida_free(&gadget_id_numbers, gadget->id_number); base-commit: 67be068d31d423b857ffd8c34dbcc093f8dfff76 --=20 2.44.0.278.ge034bb2e1d-goog