From patchwork Wed May 4 16:44:34 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 569742 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 37427C433FE for ; Wed, 4 May 2022 17:07:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356102AbiEDRLL (ORCPT ); Wed, 4 May 2022 13:11:11 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39256 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1356822AbiEDRJp (ORCPT ); Wed, 4 May 2022 13:09:45 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 50587220D0; Wed, 4 May 2022 09:55:50 -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 E02DA616F8; Wed, 4 May 2022 16:55:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 37142C385AA; Wed, 4 May 2022 16:55:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1651683349; bh=RxD54wOIf+gtesh7VHfBEjiXkcaf7g6pr7I4+AwcUM8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PmmLH9MD5cPnUF+CNIlgo3DUUq533LWFz3zv/hea2WdPZKnW+PCWyaM5216N41SRO dOscUOsUM8QxHwTF/EIRg1YpvbWgFl/+NIN0LhnPZP+xxq39va9rlvY3dj/cKiWqbQ MaYjTSOBEce7J7XyL+qaeF6fShRpINsI02/fojbc= 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 5.17 036/225] serial: 8250: Also set sticky MCR bits in console restoration Date: Wed, 4 May 2022 18:44:34 +0200 Message-Id: <20220504153113.425360432@linuxfoundation.org> X-Mailer: git-send-email 2.36.0 In-Reply-To: <20220504153110.096069935@linuxfoundation.org> References: <20220504153110.096069935@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); } /*