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=-6.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 98A80C677D4 for ; Mon, 8 Oct 2018 18:34:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DA452087D for ; Mon, 8 Oct 2018 18:34:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="WlDVG/gK" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 5DA452087D Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727854AbeJIBrg (ORCPT ); Mon, 8 Oct 2018 21:47:36 -0400 Received: from mail.kernel.org ([198.145.29.99]:58914 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726665AbeJIBrg (ORCPT ); Mon, 8 Oct 2018 21:47:36 -0400 Received: from localhost (ip-213-127-77-176.ip.prioritytelecom.net [213.127.77.176]) (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 19B7D2087D; Mon, 8 Oct 2018 18:34:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1539023673; bh=kcndAOFQp1uzuylPVkh24vusVWzAQ4R8E24MLeOrH9Y=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=WlDVG/gKDabndkCTO5DfZ3qx0GBIGR2DeQmgTf3KFrMKuIjeBpl2A3Zr+jkEZQrSH BZ5NhRgsgdhV9xszMEoQdSNeykWbzza+D8AayOxaVoK4sWWQVEhPxD3xtFL7IuSFxy PCXXVARW7X7f3ns5RqKREqbkdLuj4GtQDvuMZKNQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Wessel , Christophe Leroy Subject: [PATCH 4.4 044/113] serial: cpm_uart: return immediately from console poll Date: Mon, 8 Oct 2018 20:30:45 +0200 Message-Id: <20181008175533.058054239@linuxfoundation.org> X-Mailer: git-send-email 2.19.0 In-Reply-To: <20181008175530.864641368@linuxfoundation.org> References: <20181008175530.864641368@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.4-stable review patch. If anyone has any objections, please let me know. ------------------ From: Christophe Leroy commit be28c1e3ca29887e207f0cbcd294cefe5074bab6 upstream. kgdb expects poll function to return immediately and returning NO_POLL_CHAR when no character is available. Fixes: f5316b4aea024 ("kgdb,8250,pl011: Return immediately from console poll") Cc: Jason Wessel Cc: Signed-off-by: Christophe Leroy Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/cpm_uart/cpm_uart_core.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) --- a/drivers/tty/serial/cpm_uart/cpm_uart_core.c +++ b/drivers/tty/serial/cpm_uart/cpm_uart_core.c @@ -1068,8 +1068,8 @@ static int poll_wait_key(char *obuf, str /* Get the address of the host memory buffer. */ bdp = pinfo->rx_cur; - while (bdp->cbd_sc & BD_SC_EMPTY) - ; + if (bdp->cbd_sc & BD_SC_EMPTY) + return NO_POLL_CHAR; /* If the buffer address is in the CPM DPRAM, don't * convert it. @@ -1104,7 +1104,11 @@ static int cpm_get_poll_char(struct uart poll_chars = 0; } if (poll_chars <= 0) { - poll_chars = poll_wait_key(poll_buf, pinfo); + int ret = poll_wait_key(poll_buf, pinfo); + + if (ret == NO_POLL_CHAR) + return ret; + poll_chars = ret; pollp = poll_buf; } poll_chars--;