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 EE530361649 for ; Wed, 18 Mar 2026 07:43:00 +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=1773819781; cv=none; b=ejsuegCkzrS5W3QgoMPRB6oWqKvhnUh+ylPzhxgfgPJLC4ch35MzECoTOJ/ETeuNL3zr76IYr9OmlpS1jTnKohDOijX4kX94ZrdLAvOkaKkLj+VZatslZmpuY3DihwYJUAQIikhrJCb6JZsZa9NPC59u7bl/jLoU1ebCEWcupdE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773819781; c=relaxed/simple; bh=FjvdqkbAnoJYmzumL6p/BibiNCrIHozXex+jsqN+JEE=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=eAbuPixgIgC1L+RnWLJQyIsDRqil4idLSm2ey5sJI1rVQ8N9xOkG+A/KA3GTnNZQBsmXeldL7yJ00B7rgh8nJkMh6b0o478dTGxoAx1JHp8cInZjmYMYjmQrRmZWr1ozooW0OcmQy0TIEFKEecjeSKm3BxnSV95ypjcQSPPjHMM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=uq35wEC4; 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="uq35wEC4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8D40BC19421; Wed, 18 Mar 2026 07:43:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773819780; bh=FjvdqkbAnoJYmzumL6p/BibiNCrIHozXex+jsqN+JEE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=uq35wEC4COgbHwhgr2YWSgsdekwpZvDWr0zhsmGZcvtM4weT3V4XmcAGfbH0kF5Pe usd8/WsDFtNYS9FvP3KwcDPIhqIxzYlKNw3kPgwfKvo5ORUeJFv/ba/E0plwdJwgnv LbLFeMyaLrF/WWPS1ou69w1CH5FI7ZAxXKEpDBhkv8FOPzJ+VPa9i1K5MqZlGVvN7v eKGCqhlAV904qoDMLuwomKNIFP3sV0cQFN8PyhLpI/AIzu7d2TDCSSFx1ZcR8Sn8Ma DPBw5qKfmINieTCh/GBg5YYdHnY7sUvaIzO1fNgO/h79KylQBYbrm/tC1UyKjmR109 vRJ9fFgyoK3hg== Received: from johan by xi.lan with local (Exim 4.98.2) (envelope-from ) id 1w2lYP-000000004bE-3zJh; Wed, 18 Mar 2026 08:42:57 +0100 Date: Wed, 18 Mar 2026 08:42:57 +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: Hi Peter, On Wed, Mar 18, 2026 at 08:46:28AM +0800, PS10 PETER HONG 洪繼澤 wrote: > Johan Hovold 於 2026/3/17 下午 03:22 寫道: > > On Tue, Mar 17, 2026 at 10:21:17AM +0800, PS10 PETER HONG 洪繼澤 wrote: > >> 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. > Typical users are unlikely to encounter this, but one of our customers is > currently facing the issue. They have requested that we submit this patch to > the stable tree so they can utilize the mainstream driver without needing a > separate vendor driver. > > In theory, applying this patch will improve the product's overall stability. > We would like to see this integrated into the mainstream kernel tree. Sounds good. Johan