From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 35C30CA0EC8 for ; Mon, 11 Sep 2023 21:20:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344424AbjIKVOF (ORCPT ); Mon, 11 Sep 2023 17:14:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44602 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235675AbjIKJTV (ORCPT ); Mon, 11 Sep 2023 05:19:21 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91764CD3; Mon, 11 Sep 2023 02:19:16 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2A538C433C7; Mon, 11 Sep 2023 09:19:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1694423956; bh=CMfUhNrtWuDI24j8Rms6Yate8XX09AcwZIWD3r2Z/zQ=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QmoFmUhxt/yiEd8G4jeOoUDXygJumzb975APomu67gdlwxo5cS2WCXKyVSTrBqa/M NR4IkGbrcCIzRa5UWolX8IyFd5w/w+wzMiEFpXCRf/nP6lLHaHpfmnD4josve/7vFm MYUzhzVJaHdlkUeAiGNmJNunEe9UeIf/Fxt3k/MWPuMSmB8Mi/9FvNpBezFQhKKjf/ QotFPklwBoxQ2wGiLd/AhmauC3KX10AJ6ZJRYfYUIugPeITN9qdKwd5ZCj2u1d3W9y 6ciI1UHwEy6LiLKoT/bNyVPb/lpwXHo77YK1VVQUV9kZ65C5/QCx7d1+U1L2BkTJGJ 8nC3vpdKXpiBw== Received: from johan by xi.lan with local (Exim 4.96) (envelope-from ) id 1qfd4b-00005f-0p; Mon, 11 Sep 2023 11:19:13 +0200 Date: Mon, 11 Sep 2023 11:19:13 +0200 From: Johan Hovold To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Dan Drown , Oliver Neukum , Greg Kroah-Hartman , linux-usb@vger.kernel.org Subject: Re: [PATCH AUTOSEL 6.4 24/25] usb: cdc-acm: move ldisc dcd notification outside of acm's read lock Message-ID: References: <20230909003715.3579761-1-sashal@kernel.org> <20230909003715.3579761-24-sashal@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230909003715.3579761-24-sashal@kernel.org> Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Fri, Sep 08, 2023 at 08:37:12PM -0400, Sasha Levin wrote: > From: Dan Drown > > [ Upstream commit f72ae60881ff685004d7de7152517607fcd9968f ] > > dcd_change notification call moved outside of the acm->read_lock > to protect any future tty ldisc that calls wait_serial_change() > > Signed-off-by: Dan Drown > Acked-by: Oliver Neukum > Link: https://lore.kernel.org/r/ZN1zV/zjPgpGlHXo@vps3.drown.org > Signed-off-by: Greg Kroah-Hartman > Signed-off-by: Sasha Levin > --- > drivers/usb/class/cdc-acm.c | 10 ++++++++++ > 1 file changed, 10 insertions(+) > > diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c > index 11da5fb284d0a..ca51230f44409 100644 > --- a/drivers/usb/class/cdc-acm.c > +++ b/drivers/usb/class/cdc-acm.c > @@ -318,6 +318,16 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf) > } > > difference = acm->ctrlin ^ newctrl; > + > + if ((difference & USB_CDC_SERIAL_STATE_DCD) && acm->port.tty) { > + struct tty_ldisc *ld = tty_ldisc_ref(acm->port.tty); > + if (ld) { > + if (ld->ops->dcd_change) > + ld->ops->dcd_change(acm->port.tty, newctrl & USB_CDC_SERIAL_STATE_DCD); > + tty_ldisc_deref(ld); > + } > + } > + > spin_lock_irqsave(&acm->read_lock, flags); > acm->ctrlin = newctrl; > acm->oldcount = acm->iocount; This is a fix for a commit in 6.6-rc1 (3b563b901eef ("usb: cdc-acm: add PPS support")) so a backport of it makes no sense. Please drop. Johan