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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3A44AC4363A for ; Thu, 29 Oct 2020 00:58:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D89C9207BC for ; Thu, 29 Oct 2020 00:58:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603933121; bh=Cr3GbSvPVi9CvgpYlsf2eGVsINRQhY8Kv9mUdRAm0g0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=u2cQFtNhWM54d81Q3aj/URZYPudnznRsZq4CjXqo6/icZLVKmtNhHbsBeZzLM6frj rREJvz/NbgzaooZ/2b+NXHdsCqP9tzC65/TOCFnL+YLSWfJcvfyATYRnuHOyfzYSL7 Vpwyqr7jIeURHyCzyKdsr68QpUi6M1zTO4QeIJUQ= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2403936AbgJ2A61 (ORCPT ); Wed, 28 Oct 2020 20:58:27 -0400 Received: from mail.kernel.org ([198.145.29.99]:60544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731581AbgJ1WRc (ORCPT ); Wed, 28 Oct 2020 18:17:32 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id DFA7024196; Wed, 28 Oct 2020 09:37:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603877845; bh=Cr3GbSvPVi9CvgpYlsf2eGVsINRQhY8Kv9mUdRAm0g0=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=tN83QuDr0H93aAqm3OXtncbpaQuxzmbwV96lXiSB3mn73YDX0/VAP1GEcW8UGSuwZ ua5o6WA2SKtqOa4orRM6W0Sd2CzOmkA3/0ehOaGQpMtM4fQdYaBk6574RHv/SGUvAF pbdPgqFRkURjNRxXo/ebyKMeGa1U26jHSTNfIUbs= Date: Wed, 28 Oct 2020 10:38:18 +0100 From: Greg KH To: Johan Hovold Cc: linux-usb@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] USB: serial: digi_acceleport: fix write-wakeup deadlocks Message-ID: <20201028093818.GB1953863@kroah.com> References: <20201026104306.29576-1-johan@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20201026104306.29576-1-johan@kernel.org> Precedence: bulk List-ID: X-Mailing-List: linux-usb@vger.kernel.org On Mon, Oct 26, 2020 at 11:43:06AM +0100, Johan Hovold wrote: > The driver must not call tty_wakeup() while holding its private lock as > line disciplines are allowed to call back into write() from > write_wakeup(), leading to a deadlock. > > Also remove the unneeded work struct that was used to defer wakeup in > order to work around a possible race in ancient times (see comment about > n_tty write_chan() in commit 14b54e39b412 ("USB: serial: remove > changelogs and old todo entries")). > > Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") > Cc: stable@vger.kernel.org > Signed-off-by: Johan Hovold > --- > drivers/usb/serial/digi_acceleport.c | 45 ++++++++-------------------- > 1 file changed, 13 insertions(+), 32 deletions(-) Reviewed-by: Greg Kroah-Hartman