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: 1414811 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-process-083081@patchwork2.kernel.org Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) by patchwork2.kernel.org (Postfix) with ESMTP id 420BADFFCF for ; Thu, 6 Sep 2012 13:04:36 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1T9bgj-0001XN-M5; Thu, 06 Sep 2012 13:00:08 +0000 Received: from na3sys009aog114.obsmtp.com ([74.125.149.211]) by merlin.infradead.org with smtps (Exim 4.76 #1 (Red Hat Linux)) id 1T9bY2-00032x-Iy for linux-arm-kernel@lists.infradead.org; Thu, 06 Sep 2012 12:51:09 +0000 Received: from mail-lpp01m010-f49.google.com ([209.85.215.49]) (using TLSv1) by na3sys009aob114.postini.com ([74.125.148.12]) with SMTP ID DSNKUEicOCw1Qio39mQcCDddxjVqEPB4YU8b@postini.com; Thu, 06 Sep 2012 05:51:06 PDT Received: by lagu2 with SMTP id u2so1046675lag.36 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=Dg+J6oO9ThHSGi3VphOcZ2uJsCuD3gRNP9zV0L3aPyLMUZZcK8Yofc7U20hsEkvd+s fa69YHY7dZwkbQrzmaNjT2fNdGmsFSXD4hXMa+tbErLybvnGDtyud71fakGhoF0I5jXk 6b46YafAWbBYkoWxnP0bt3oZ+6q9Ty5f/WaaOuY3uuLWLHCm5dWySocEJscE+MEu2LK2 e3nNUTC7d68zZ4s8FrxXfM+kT8/v7nuAQvVKwKgG6NwKnqSyEgiZ1xvrW9vRr4mJzabz FNN2rTSOMOd4qTnDtCzDb7fQRoulnkPtevkO+lGvtxDMxfq2iZK/XnRD7N9MDF14rSlf 4y7g== 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 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: ALoCoQnb0ul1In15qG7MG0Exul2FAF5d5vIkVOHtx7sig0cBUm5WvKqsu6eg4yVHVP6q4Sxz9BjO X-Spam-Note: CRM114 invocation failed X-Spam-Score: -4.2 (----) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-4.2 points) pts rule name description ---- ---------------------- -------------------------------------------------- -2.3 RCVD_IN_DNSWL_MED RBL: Sender listed at http://www.dnswl.org/, medium trust [74.125.149.211 listed in list.dnswl.org] -0.0 SPF_PASS SPF: sender matches SPF record -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: Kevin Hilman , Tony Lindgren , Linux Kernel Mailing List , Felipe Balbi , Santosh Shilimkar , linux-serial@vger.kernel.org, Sourav Poddar , Linux OMAP Mailing List , Shubhrajyoti Datta , Linux ARM Kernel Mailing List , alan@linux.intel.com X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.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; }