From patchwork Mon Sep 10 04:13:35 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anton Vorontsov X-Patchwork-Id: 1429601 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 70FABDF28C for ; Mon, 10 Sep 2012 04:19:29 +0000 (UTC) Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.76 #1 (Red Hat Linux)) id 1TAvQ4-0002CT-85; Mon, 10 Sep 2012 04:16:20 +0000 Received: from mail-pb0-f49.google.com ([209.85.160.49]) by merlin.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1TAvPr-0001qa-LA for linux-arm-kernel@lists.infradead.org; Mon, 10 Sep 2012 04:16:09 +0000 Received: by mail-pb0-f49.google.com with SMTP id rq8so2004197pbb.36 for ; Sun, 09 Sep 2012 21:16:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=date:from:to:cc:subject:message-id:references:mime-version :content-type:content-disposition:in-reply-to:user-agent :x-gm-message-state; bh=UHQK30vZizGwnzAVRoEjF8rTm3DZJk8nIU/B02LymIU=; b=mQDCmuOgGdoZMypdoDyxFpl1lSJAiz4h+RzfU3Z/UthOi9viEgIDc/I9/uCJnGX5l0 XiABGkz61bIa2Hi9qG0JcPOelMseQL2w3MXrqMZVd0kq+lg4qN7NYMEgOVFjT2JoA5fn Vqo1IWO2n9OYqmgnDDcrZu0fJPYftapKGarqCtWU/t35PHn5QKH2Qpvbl3myazmZrRXA jOZ5Iw1yoZ0JpefWl6nBXVfnytATP0qYa+sNQPmM/2SFiPOHKdEFXS9MoqDm+G/YVQ10 EOjSvwU+wLmp7yDm/ymu/MBJ8n0CsxddmI3Eoys8lcIWOMBhIMQYpoPZZGkx3X9XjK/r uZ/w== Received: by 10.68.223.163 with SMTP id qv3mr3872034pbc.101.1347250567291; Sun, 09 Sep 2012 21:16:07 -0700 (PDT) Received: from localhost (ip-64-134-230-8.public.wayport.net. [64.134.230.8]) by mx.google.com with ESMTPS id qf4sm7443341pbc.1.2012.09.09.21.16.06 (version=TLSv1/SSLv3 cipher=OTHER); Sun, 09 Sep 2012 21:16:07 -0700 (PDT) Date: Sun, 9 Sep 2012 21:13:35 -0700 From: Anton Vorontsov To: Andrew Morton , Russell King , Jason Wessel , Greg Kroah-Hartman , Alan Cox Subject: [PATCH 06/14] tty/serial/core: Introduce poll_init callback Message-ID: <20120910041335.GF29537@lizard> References: <20120910040802.GA1261@lizard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120910040802.GA1261@lizard> User-Agent: Mutt/1.5.21 (2010-09-15) X-Gm-Message-State: ALoCoQmP2ybZ/aCFVTMCZTO6O+cifdroCrvyMhjzycLe91xkrIGczPKPxZI+n8bHNTKQBaMugnqq X-Spam-Note: CRM114 invocation failed X-Spam-Score: -2.6 (--) X-Spam-Report: SpamAssassin version 3.3.2 on merlin.infradead.org summary: Content analysis details: (-2.6 points) pts rule name description ---- ---------------------- -------------------------------------------------- -0.7 RCVD_IN_DNSWL_LOW RBL: Sender listed at http://www.dnswl.org/, low trust [209.85.160.49 listed in list.dnswl.org] -1.9 BAYES_00 BODY: Bayes spam probability is 0 to 1% [score: 0.0000] Cc: linaro-kernel@lists.linaro.org, patches@linaro.org, Brian Swetland , linux-kernel@vger.kernel.org, Arve =?utf-8?B?SGrDuG5uZXbDpWc=?= , John Stultz , linux-serial@vger.kernel.org, Colin Cross , kgdb-bugreport@lists.sourceforge.net, kernel-team@android.com, linux-arm-kernel@lists.infradead.org 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: , Sender: linux-arm-kernel-bounces@lists.infradead.org Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org It was noticed that polling drivers (like KGDB) are not able to use serial ports if the ports were not previously initialized via console. I.e. when booting with console=ttyAMA0 kgdboc=ttyAMA0, everything works fine, but with console=ttyFOO kgdboc=ttyAMA0, the kgdboc doesn't work. This is because we don't initialize the hardware. Calling ->startup() is not an option, because drivers request interrupts there, and drivers fail to handle situations when tty isn't opened with interrupts enabled. So, we have to implement a new callback (actually, tty_ops already have a similar callback), which does everything needed to initialize just the hardware. Signed-off-by: Anton Vorontsov --- drivers/tty/serial/serial_core.c | 15 +++++++++++++++ include/linux/serial_core.h | 1 + 2 files changed, 16 insertions(+) diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c index a21dc8e..cba8443 100644 --- a/drivers/tty/serial/serial_core.c +++ b/drivers/tty/serial/serial_core.c @@ -2108,11 +2108,13 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) { struct uart_driver *drv = driver->driver_state; struct uart_state *state = drv->state + line; + struct tty_port *tport; struct uart_port *port; int baud = 9600; int bits = 8; int parity = 'n'; int flow = 'n'; + int ret; if (!state || !state->uart_port) return -1; @@ -2121,6 +2123,19 @@ static int uart_poll_init(struct tty_driver *driver, int line, char *options) if (!(port->ops->poll_get_char && port->ops->poll_put_char)) return -1; + tport = &state->port; + if (!(tport->flags & ASYNC_INITIALIZED) && port->ops->poll_init) { + mutex_lock(&tport->mutex); + ret = port->ops->poll_init(port); + /* + * We don't set ASYNCB_INITIALIZED as we only initialized the + * hw, e.g. state->xmit is still uninitialized. + */ + mutex_unlock(&tport->mutex); + if (ret) + return ret; + } + if (options) { uart_parse_options(options, &baud, &parity, &bits, &flow); return uart_set_options(port, NULL, baud, parity, bits, flow); diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h index 0253c20..3642710 100644 --- a/include/linux/serial_core.h +++ b/include/linux/serial_core.h @@ -274,6 +274,7 @@ struct uart_ops { int (*verify_port)(struct uart_port *, struct serial_struct *); int (*ioctl)(struct uart_port *, unsigned int, unsigned long); #ifdef CONFIG_CONSOLE_POLL + int (*poll_init)(struct uart_port *); void (*poll_put_char)(struct uart_port *, unsigned char); int (*poll_get_char)(struct uart_port *); #endif