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=-3.9 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED 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 B100DC07E85 for ; Sun, 9 Dec 2018 21:58:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 8040520661 for ; Sun, 9 Dec 2018 21:58:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8040520661 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=decadent.org.uk 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 S1726766AbeLIVzj (ORCPT ); Sun, 9 Dec 2018 16:55:39 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:35278 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726531AbeLIVzX (ORCPT ); Sun, 9 Dec 2018 16:55:23 -0500 Received: from pub.yeoldevic.com ([81.174.156.145] helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1gW72l-0002ir-4y; Sun, 09 Dec 2018 21:55:19 +0000 Received: from ben by deadeye with local (Exim 4.91) (envelope-from ) id 1gW72i-0003a0-9Q; Sun, 09 Dec 2018 21:55:16 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, "Jason Wessel" , "Greg Kroah-Hartman" , "Christophe Leroy" Date: Sun, 09 Dec 2018 21:50:33 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 245/328] serial: cpm_uart: return immediately from console poll In-Reply-To: X-SA-Exim-Connect-IP: 81.174.156.145 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.62-rc1 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 Signed-off-by: Christophe Leroy Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ben Hutchings --- 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 @@ -1062,8 +1062,8 @@ 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. @@ -1097,7 +1097,11 @@ 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--;