From patchwork Wed May 4 16:43:44 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 569812 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 1E1DFC433F5 for ; Wed, 4 May 2022 17:02:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232463AbiEDRFh (ORCPT ); Wed, 4 May 2022 13:05:37 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51354 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1355444AbiEDRE2 (ORCPT ); Wed, 4 May 2022 13:04:28 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [IPv6:2604:1380:4641:c500::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3F9B54EA23; Wed, 4 May 2022 09:53:03 -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 940B3617DE; Wed, 4 May 2022 16:53:00 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E1A6CC385A4; Wed, 4 May 2022 16:52:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683180; bh=RxD54wOIf+gtesh7VHfBEjiXkcaf7g6pr7I4+AwcUM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=I6nlNeODBqhzd3ClvX6epppH5w1bJRUuwozvWubRaaPse6vTYd3y4xaEjWFCqf7Ax Q5u/kHw1z1HVXjg4go7dj6PQVnvR/MB87CAEgB9Ty9bbpDgtazB6sD1S1yw1tPc9/T ly23VCySTQ98NVmKwxqEGTzkkFFZeFWgOiL53+mk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "Maciej W. Rozycki" , Andy Shevchenko Subject: [PATCH 5.15 031/177] serial: 8250: Also set sticky MCR bits in console restoration Date: Wed, 4 May 2022 18:43:44 +0200 Message-Id: <20220504153055.785959388@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153053.873100034@linuxfoundation.org> References: <20220504153053.873100034@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Maciej W. Rozycki commit 6e6eebdf5e2455f089ccd000754a0deaeb79af82 upstream. Sticky MCR bits are lost in console restoration if console suspending has been disabled. This currently affects the AFE bit, which works in combination with RTS which we set, so we want to make sure the UART retains control of its FIFO where previously requested. Also specific drivers may need other bits in the future. Signed-off-by: Maciej W. Rozycki Fixes: 4516d50aabed ("serial: 8250: Use canary to restart console after suspend") Cc: stable@vger.kernel.org # v4.0+ Reviewed-by: Andy Shevchenko Link: https://lore.kernel.org/r/alpine.DEB.2.21.2204181518490.9383@angie.orcam.me.uk Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/8250/8250_port.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/tty/serial/8250/8250_port.c +++ b/drivers/tty/serial/8250/8250_port.c @@ -3340,7 +3340,7 @@ static void serial8250_console_restore(s serial8250_set_divisor(port, baud, quot, frac); serial_port_out(port, UART_LCR, up->lcr); - serial8250_out_MCR(up, UART_MCR_DTR | UART_MCR_RTS); + serial8250_out_MCR(up, up->mcr | UART_MCR_DTR | UART_MCR_RTS); } /*