From nobody Fri Oct 3 20:58:16 2025 Received: from mail-m19731105.qiye.163.com (mail-m19731105.qiye.163.com [220.197.31.105]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id A6B8217BD6; Mon, 25 Aug 2025 04:30:57 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.105 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756096263; cv=none; b=hlgoMaBsJiy1WqFPWA/jS3y8u76w8PQbmqgRmKStkv/Jh3DRZuFySM+KSpShnmanRpUT6mTTeF1c4yPnaZIPtmszRaczLeog6QVaM35GIcUPpnavZI2iIxmzBDtzsSBOerUCX6iatrpRAAzglPNeww0AAzLfWjuqcN854chY8ss= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756096263; c=relaxed/simple; bh=pvUbiBoxVxw7aALluWoxgbFrYS9S+eeN8dUs+2qf1DM=; h=From:To:Cc:Subject:Date:Message-Id; b=YUbT5O/39EjAGg4XQ0Ayx+g7fxc8cpuAYgVY+bLBxYUuBF7XnS59iCoKt/k8ebcM47jQZDD3g1EDDUncRqe4oJ/AKHPpf0UmjwOMWol0aubG1wiL5t43vAmlIu4hUsLA5i0FaUK3U2JBBKhOcdEsNTNfWTVD3nJ+MnR8JQ9qB3c= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com; spf=pass smtp.mailfrom=rock-chips.com; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b=BB3UPDiD; arc=none smtp.client-ip=220.197.31.105 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rock-chips.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=rock-chips.com header.i=@rock-chips.com header.b="BB3UPDiD" Received: from localhost.localdomain (unknown [58.22.7.114]) by smtp.qiye.163.com (Hmail) with ESMTP id 20756289a; Mon, 25 Aug 2025 12:15:33 +0800 (GMT+08:00) From: William Wu To: gregkh@linuxfoundation.org, stern@rowland.harvard.edu Cc: Chris.Wulff@biamp.com, linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, william.wu@rock-chips.com, frank.wang@rock-chips.com, jianwei.zheng@rock-chips.com, yue.long@rock-chips.com Subject: [PATCH v2] usb: gadget: f_hid: Fix zero length packet transfer Date: Mon, 25 Aug 2025 12:14:26 +0800 Message-Id: <1756095266-5736-1-git-send-email-william.wu@rock-chips.com> X-Mailer: git-send-email 2.0.0 X-HM-Tid: 0a98df70428d09d4kunm613c14bd1b23f2c X-HM-MType: 1 X-HM-Spam-Status: e1kfGhgUHx5ZQUpXWQgPGg8OCBgUHx5ZQUlOS1dZFg8aDwILHllBWSg2Ly tZV1koWUFDSUNOT01LS0k3V1ktWUFJV1kPCRoVCBIfWUFZQ0hKSFYdHUwaQktOHkIZGh5WFRQJFh oXVRMBExYaEhckFA4PWVdZGBILWUFZTkNVSUlVTFVKSk9ZV1kWGg8SFR0UWUFZT0tIVUpLSU9PT0 hVSktLVUpCS0tZBg++ DKIM-Signature: a=rsa-sha256; b=BB3UPDiDt8ZdroPQzd4V3FX/nFKv/gpEnmAIRpDCWo1VbCMJmGRXY8h4UI77SFHyRnlaSim7EP8yMuuAx6YOIIM+Rk0655BeL0EvKsfG7kM7cq6zn3ri/RQ0pjMbhLrxTNenmMx6K/RCsRcaMQk/uoWee5GtG9tFsgZoOJ2TobY=; s=default; c=relaxed/relaxed; d=rock-chips.com; v=1; bh=2CAjSe2JbkI8B9/9cyiD0mICHc+A2sNBmU9o8PPAo+g=; h=date:mime-version:subject:message-id:from; Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Set the hid req->zero flag of ep0/in_ep to true by default, then the UDC drivers can transfer a zero length packet at the end if the hid transfer with size divisible to EPs max packet size according to the USB 2.0 spec. Signed-off-by: William Wu --- drivers/usb/gadget/function/f_hid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/function/f_hid.c b/drivers/usb/gadget/funct= ion/f_hid.c index 8e1d1e8..307ea56 100644 --- a/drivers/usb/gadget/function/f_hid.c +++ b/drivers/usb/gadget/function/f_hid.c @@ -511,7 +511,7 @@ static ssize_t f_hidg_write(struct file *file, const ch= ar __user *buffer, } =20 req->status =3D 0; - req->zero =3D 0; + req->zero =3D 1; req->length =3D count; req->complete =3D f_hidg_req_complete; req->context =3D hidg; @@ -967,7 +967,7 @@ static int hidg_setup(struct usb_function *f, return -EOPNOTSUPP; =20 respond: - req->zero =3D 0; + req->zero =3D 1; req->length =3D length; status =3D usb_ep_queue(cdev->gadget->ep0, req, GFP_ATOMIC); if (status < 0) --=20 2.0.0