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 AAFDECCA479 for ; Mon, 20 Jun 2022 08:17:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239814AbiFTIRj (ORCPT ); Mon, 20 Jun 2022 04:17:39 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35712 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239830AbiFTIRi (ORCPT ); Mon, 20 Jun 2022 04:17:38 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0A21111829 for ; Mon, 20 Jun 2022 01:17:38 -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 9A86561299 for ; Mon, 20 Jun 2022 08:17:37 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A648C3411B; Mon, 20 Jun 2022 08:17:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1655713057; bh=zDIBNNl8Eh/fJHsZpblkfHQKZq5hkKMRw/MXYywQuGk=; h=Subject:To:Cc:From:Date:From; b=O8WVaYz3Y9UxsbQIM+V3JLVHLMh3wPZpN0z7FSnwGuoMZyROTk699CmF6/Xw5hbZv n/Bv/e/DeJEvbg23jt9BqenNRbhNUP/C9k6L0UDsdyxPOjiXOzwFDpkQtvu5UsETwv iocP3iFov3Herk12GXGcwjT0AqwcSJxuod0PpKWQ= Subject: FAILED: patch "[PATCH] serial: 8250: Store to lsr_save_flags after lsr read" failed to apply to 4.19-stable tree To: ilpo.jarvinen@linux.intel.com, gregkh@linuxfoundation.org, stable@kernel.org, u.kleine-koenig@pengutronix.de, u.kleine-koenig@penugtronix.de Cc: From: Date: Mon, 20 Jun 2022 10:17:18 +0200 Message-ID: <16557130384481@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From be03b0651ffd8bab69dfd574c6818b446c0753ce Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= Date: Fri, 20 May 2022 13:35:41 +0300 Subject: [PATCH] serial: 8250: Store to lsr_save_flags after lsr read MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 diff --git a/drivers/tty/serial/8250/8250_port.c b/drivers/tty/serial/8250/8250_port.c index 78b6dedc43e6..8f32fe9e149e 100644 --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -1517,6 +1517,8 @@ static inline void __stop_tx(struct uart_8250_port *p) unsigned char lsr = serial_in(p, UART_LSR); u64 stop_delay = 0; + p->lsr_saved_flags |= lsr & LSR_SAVE_FLAGS; + if (!(lsr & UART_LSR_THRE)) return; /*