From patchwork Thu Sep 6 12:45:36 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felipe Balbi X-Patchwork-Id: 1414341 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by patchwork2.kernel.org (Postfix) with ESMTP id 4F70DDFFCF for ; Thu, 6 Sep 2012 12:52:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755642Ab2IFMwg (ORCPT ); Thu, 6 Sep 2012 08:52:36 -0400 Received: from na3sys009aog113.obsmtp.com ([74.125.149.209]:40577 "EHLO na3sys009aog113.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755671Ab2IFMvF (ORCPT ); Thu, 6 Sep 2012 08:51:05 -0400 Received: from mail-lb0-f174.google.com ([209.85.217.174]) (using TLSv1) by na3sys009aob113.postini.com ([74.125.148.12]) with SMTP ID DSNKUEicOCw1Qio39mQcCDddxjVqEPB4YU8b@postini.com; Thu, 06 Sep 2012 05:51:05 PDT Received: by lbbgj3 with SMTP id gj3so1101558lbb.19 for ; Thu, 06 Sep 2012 05:51:03 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references :x-gm-message-state; bh=LbdtcqYLuyGuh47C0r+A3COoCZ6GGgkq+KDmFFgCLOk=; b=c8i2zoI3pwi/haCVV1XKHayUYXpwH6mpJZrq1EDLWFEeEOs8xOnnNEz+d5WM+fZQth HNRabI6ftq/VS9/AhmT5K7o6E/uXX2ukvfuRekaFS9ktnrJJXVx9ElyxhWaaGHT6QKfW szp/agflQAiFbfUEVUvXXvSFlKMTcUJm5V6O4AF47HdP8nCWK+77y0zEuFR+AK3J1qkK en/N2w7PdalJwfOfUTCst5M1WyH40MzMOnRkeoW93nBynyOjsbgg4sb7CdM3BI2RzF6e fpmUokTlGJD0TpI4te94tMDuOsn5OdBk6ALXkROe5I5dKyRfS1Umx9fkOHYRoW5y2Mf+ Rrqw== Received: by 10.112.102.198 with SMTP id fq6mr808230lbb.135.1346935862972; Thu, 06 Sep 2012 05:51:02 -0700 (PDT) Received: from localhost (cs78217178.pp.htv.fi. [62.78.217.178]) by mx.google.com with ESMTPS id r1sm562848lbk.12.2012.09.06.05.51.01 (version=TLSv1/SSLv3 cipher=OTHER); Thu, 06 Sep 2012 05:51:02 -0700 (PDT) From: Felipe Balbi To: Greg KH Cc: alan@linux.intel.com, Tony Lindgren , Kevin Hilman , Linux OMAP Mailing List , Linux ARM Kernel Mailing List , linux-serial@vger.kernel.org, Linux Kernel Mailing List , Santosh Shilimkar , Shubhrajyoti Datta , Sourav Poddar , Felipe Balbi Subject: [PATCH v4 17/21] serial: omap: make sure to put() on poll_get_char Date: Thu, 6 Sep 2012 15:45:36 +0300 Message-Id: <1346935540-1792-18-git-send-email-balbi@ti.com> X-Mailer: git-send-email 1.7.12.rc3 In-Reply-To: <1346935540-1792-1-git-send-email-balbi@ti.com> References: <20120906122948.GC29202@arwen.pp.htv.fi> <1346935540-1792-1-git-send-email-balbi@ti.com> X-Gm-Message-State: ALoCoQlIhI722OFINwPXy9JRDu1kmEXDVurns+3F2yY0+TNl1BUSQu9LOWG4UhfwfrQLQZT2qw75 Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org if we would reach serial_omap_get_char() while Data Ready bit isn't set, we would return from it without kicking our pm timer. This would mean we would, eventually, have an unbalanced pm_runtime_get on our device which would prevent it from ever sleeping again. Tested-by: Shubhrajyoti D Signed-off-by: Felipe Balbi --- drivers/tty/serial/omap-serial.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) diff --git a/drivers/tty/serial/omap-serial.c b/drivers/tty/serial/omap-serial.c index 7531147..6a58f4f 100644 --- a/drivers/tty/serial/omap-serial.c +++ b/drivers/tty/serial/omap-serial.c @@ -1005,12 +1005,17 @@ static int serial_omap_poll_get_char(struct uart_port *port) pm_runtime_get_sync(up->dev); status = serial_in(up, UART_LSR); - if (!(status & UART_LSR_DR)) - return NO_POLL_CHAR; + if (!(status & UART_LSR_DR)) { + status = NO_POLL_CHAR; + goto out; + } status = serial_in(up, UART_RX); + +out: pm_runtime_mark_last_busy(up->dev); pm_runtime_put_autosuspend(up->dev); + return status; }