From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 07E7538C433 for ; Tue, 17 Mar 2026 07:22:58 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773732179; cv=none; b=O4TvXygFuWb7Oa6dxJNCeQoWB6KixojmrdYMlJ2VYEj3sCrAfG4E2I1vj97fVFKxLsIJMlovXGsJgctMtIfufkwq7Q8dopqhXs6orZv1THrxjHb4Ht6FtvzhdTCuIPzwW+o6Na+mggkaohU4SMnvdLaRVvVFP1cRIB/HdIWzkSE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773732179; c=relaxed/simple; bh=BEg9MEKVoGa53wgmbH/RTArYL8PbSuqzMvU/Y/4Pshw=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=njsvnipb7w4EzhOYEG/aPYdnMMAPGolV7lE1yhYTCnl5EmmJYSMMde/huzM5Lr2Sf46LA8dmI+ld+4OES55UB9OFNNtWEepd4bBHYPZIJ+kBxBhgEHP1c57RrGGA9UAUaFyWAFwvk+HlUopGyUMTHAHciXltFDg58SFqCLFl/D0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U56LDD7J; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="U56LDD7J" Received: by smtp.kernel.org (Postfix) with ESMTPSA id A4879C4CEF7; Tue, 17 Mar 2026 07:22:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773732178; bh=BEg9MEKVoGa53wgmbH/RTArYL8PbSuqzMvU/Y/4Pshw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=U56LDD7J5QcwfjmkIKjJ3zsb7luSgMkPovOu0MAkh4bdaptQdnghCwwyUXdgY1cgr qz9HmiNJKWLVw8zNNHfRmIkZ3EiNahKhof09/sqWLhEAAJMyT5VkywTfFUAGGv4y7o bNOn9DIKBit5yoUkeIvUn4pjCGXBfkKgqQGzdYqk8T4xfOvFJMrDue9bvxAG//SQGo LHYc09RqBgnxe++hVhxlaCssKTXaIRAtVT+gmhSnraHUGG/yaVlS6yGhAvgcKb54kG YQy1WLnlcguyZv7q1YHSnadezEKKA3C//yahOT62rwh5njz7t2Q9QZTHmwBQUi/gST fneF9jeKSEuYw== Received: from johan by xi.lan with local (Exim 4.98.2) (envelope-from ) id 1w2OlU-000000003kO-1JI6; Tue, 17 Mar 2026 08:22:56 +0100 Date: Tue, 17 Mar 2026 08:22:56 +0100 From: Johan Hovold To: PS10 PETER HONG =?utf-8?B?5rSq57m85r6k?= Cc: gregkh@linuxfoundation.org, sashal@kernel.org, stable@vger.kernel.org Subject: Re: Post-facto backport request: USB: serial: f81232: fix incomplete serial port generation Message-ID: References: <5bcf02b5-3fe5-466e-a1da-0e5a2e62fd5f@fintek.com.tw> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <5bcf02b5-3fe5-466e-a1da-0e5a2e62fd5f@fintek.com.tw> On Tue, Mar 17, 2026 at 10:21:17AM +0800, PS10 PETER HONG 洪繼澤 wrote: > Hi Stable Team, > > I would like to request a backport for the following commit to the > currently supported stable trees 6.1.y, 6.6.y, 6.12.y and 6.18.y > >   cd644b805da8 ("USB: serial: f81232: fix incomplete serial port > generation") > > Reason: >   This patch fixes a stability issue where Fintek F81532A/534A/535/536 >   devices fail to initialize all serial ports during fast load/unload > cycles. >   The fix involves a dummy read to clear the device's stale internal state. > > The patch should apply cleanly to most recent stable branches. My understanding was that this was only something you'd hit if you unload and reload the driver which isn't something a user would normally do. That's why I didn't add a stable tag. The diff is a bit on the bigger side but it's all straight-forward enough so I'm fine with backporting if you think it will be useful also for older kernels. Johan