From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 7809F3B42C6; Thu, 24 Sep 2026 14:23:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790259798; cv=none; b=Y7qY3X/u3jQKCmQQwN13ncEbh5+vj1CdR8r5D/+50YNt4X2/Erbk/xbRh9am8oABATH1qbF6A0REh4X8AYpUbJbWxQ3LyXT3x6xpKzEUnc/LVqRBbClAjpxcmwuEM/9ys3byXzflZ1rq2ymN+WJxvp7ld2PCgTbHNly+QUYQpWc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790259798; c=relaxed/simple; bh=GPC1yr+ZTTPDV2IqY+Tm9zUxSqdHGv82/wq619yWX9w=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=UTcEtSs/WlBLYLp05C2I3pfnz3xCoU6EU5cBfq72F5vN1DG5ixWt7/myqKigpkSk82IYdKxmlMQHfpg5f94IEc1izQjsy1IHmMsoZrVZQn5zsQM9jdyqKGHUsQlDKbna+LMNWMclKybsvDaBA7dgPc3CkZBOmD8YJjXW4P7Wn+Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=yf9+62Dr; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="yf9+62Dr" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BD851F000FF; Thu, 24 Sep 2026 14:23:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1790259792; bh=pBM8yzJ1P/YN8g9AMJ+6Lw5x7cfNoUSq+jqBG8i0rrM=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=yf9+62DrRhmwpUBlW+gMhbTsNOS1KTcXSP7BgKJPFGKHgHOehWO30BHv8nBA5C0Fh vA3q7hz1P9J9n0lzKgLHRH10MhpSQ6pROQVg48/8Pm7f4WldMXdWWNATdWP2bSGUSD pDq2K0m94tcjvwcTWhVwv3411a5gVgdJNmUqvbng= Date: Thu, 24 Sep 2026 16:22:54 +0200 From: Greg KH To: Paolo Abeni Cc: Ming Wang , netdev@vger.kernel.org, linux-usb@vger.kernel.org, stable@vger.kernel.org, Oliver Neukum , Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] net: usb: cdc_mbim: add MeiG Smart SRM821 to ZLP whitelist Message-ID: <2026092409-status-rocker-0fef@gregkh> References: <20260920074500.826121-1-wangming01@loongson.cn> <4d5e2857-e6eb-43e2-b668-83e779aaa734@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4d5e2857-e6eb-43e2-b668-83e779aaa734@redhat.com> On Thu, Sep 24, 2026 at 12:24:06PM +0200, Paolo Abeni wrote: > On 9/20/26 09:44, Ming Wang wrote: > > The MeiG Smart SRM821 5G module (0x2dee:0x4d53) crashes and drops off > > the USB bus when it receives a Zero Length Packet (ZLP) after sending > > or receiving an NTB of exactly 16384 bytes (tx_max). > > > > According to the MBIM specification, devices do not require a ZLP > > if the NTB size is exactly dwNtbOutMaxSize. However, the cdc_mbim > > driver defaults to sending ZLPs for devices not explicitly whitelisted > > to accommodate non-conformant hardware. This default behavior breaks > > the strictly conformant MeiG SRM821 module. > > > > Add this device to the ZLP conformance whitelist (cdc_mbim_info) so > > the driver will pad the NTB to avoid sending ZLPs, preventing the > > device firmware from crashing. > > > > Cc: stable@vger.kernel.org > > Signed-off-by: Ming Wang > > Before any other step, please read: > > https://elixir.bootlin.com/linux/v7.3-rc3/source/Documentation/process/maintainer-netdev.rst#L454 > > AFAICS this is actually support for additional H/W, just worded in > very unusual way: please reword the commit message accordingly and > drop stable from CC. Why drop stable from cc:? Do you not want it in any stable kernel release? Seems like it should be to me, we gladly take quirk additions and new device ids in stable kernels. thanks, greg k-h