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 A9AE1C433EF for ; Mon, 20 Jun 2022 09:38:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239417AbiFTJiJ (ORCPT ); Mon, 20 Jun 2022 05:38:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44204 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240600AbiFTJiB (ORCPT ); Mon, 20 Jun 2022 05:38:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D042A1123 for ; Mon, 20 Jun 2022 02:38:00 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 6CDF461458 for ; Mon, 20 Jun 2022 09:38:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 70377C3411B; Mon, 20 Jun 2022 09:37:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655717879; bh=bdqRLYOQfMs9KRB0hRsZr8M/8IZRrDltwiVsSVdif14=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZXZ1+id/HeTrpSZ/nfT37iSvho2VKp6lNjTfWzjQUc3ne8+QgZ7ZxhEAZQsOp7ENu ds7RGA23PGL3CIIkNFl/Xxts06qEsVHet1FVtorEugMbQwyN6xDprVnpBmedjTrEJQ JePTa5sNA/O53ewjHzK06lShL2vUiBjdcM7xN8Hg= Date: Mon, 20 Jun 2022 11:37:56 +0200 From: Greg Kroah-Hartman To: Ilpo =?iso-8859-1?Q?J=E4rvinen?= Cc: stable@kernel.org, u.kleine-koenig@pengutronix.de, stable@vger.kernel.org Subject: Re: [PATCH stable-5.18 (and below)] serial: 8250: Store to lsr_save_flags after lsr read Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org On Mon, Jun 20, 2022 at 11:42:31AM +0300, Ilpo Järvinen wrote: > [ Upstream commit be03b0651ffd8bab69dfd574c6818b446c0753ce ] > > Not all LSR register flags are preserved across reads. Therefore, LSR > readers must store the non-preserved bits into lsr_save_flags. > > This fix was initially mixed into feature commit f6f586102add ("serial: > 8250: Handle UART without interrupt on TEMT using em485"). However, > that feature change had a flaw and it was reverted to make room for > simpler approach providing the same feature. The embedded fix got > reverted with the feature change. > > Re-add the lsr_save_flags fix and properly mark it's a fix. > > Link: https://lore.kernel.org/all/1d6c31d-d194-9e6a-ddf9-5f29af829f3@linux.intel.com/T/#m1737eef986bd20cf19593e344cebd7b0244945fc > Fixes: e490c9144cfa ("tty: Add software emulated RS485 support for 8250") > Cc: stable > Acked-by: Uwe Kleine-König > Signed-off-by: Uwe Kleine-König > Signed-off-by: Ilpo Järvinen > Link: https://lore.kernel.org/r/f4d774be-1437-a550-8334-19d8722ab98c@linux.intel.com > Signed-off-by: Greg Kroah-Hartman > --- > > Here's the backport for 5.18. I think it applies fine to older kernel > versions too. Thanks for the backport, now all queued up. greg k-h