Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753171AbaJQNNQ (ORCPT ); Fri, 17 Oct 2014 09:13:16 -0400 Received: from smtp.codeaurora.org ([198.145.11.231]:37861 "EHLO smtp.codeaurora.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753096AbaJQNNL (ORCPT ); Fri, 17 Oct 2014 09:13:11 -0400 From: Kumar Gala To: gregkh@linuxfoundation.org Cc: Kumar Gala , linux-kernel@vger.kernel.org, linux-arm-msm , linux-arm-kernel@lists.infradead.org Subject: [PATCH] tty: serial: msm: Fix lock init issue with earlycon Date: Fri, 17 Oct 2014 08:13:08 -0500 Message-Id: <1413551588-14877-1-git-send-email-galak@codeaurora.org> X-Mailer: git-send-email 1.8.2.1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org With CONFIG_DEBUG_SPINLOCK enabled we see: BUG: spinlock bad magic on CPU#0, swapper/0 lock: early_console_dev+0x8/0x160, .magic: 00000000, .owner: /-1, .owner_cpu: 0 CPU: 0 PID: 0 Comm: swapper Not tainted 3.17.0-09733-gb446b33-dirty #18 Call trace: [] dump_backtrace+0x0/0x140 [] show_stack+0x10/0x1c [] dump_stack+0x74/0xb8 [] spin_dump+0x78/0x88 [] spin_bug+0x24/0x34 [] do_raw_spin_lock+0x30/0x158 [] _raw_spin_lock+0x1c/0x2c [] __msm_console_write+0x68/0x154 [] msm_serial_early_write_dm+0x14/0x20 [] call_console_drivers.constprop.23+0xa4/0xc4 [] console_unlock+0x2a8/0x330 [] register_console+0x26c/0x338 [] setup_earlycon+0x2c0/0x300 [] msm_serial_dm_setup_earlycon+0x18/0x24 [] do_early_param+0x84/0xd0 [] parse_args+0x2b4/0x3ec [] parse_early_options+0x2c/0x38 [] parse_early_param+0x34/0x50 [] setup_arch+0x290/0x604 [] start_kernel+0x94/0x38c As the earlycon write function for msm requires a lock, we need to init it as part of the setup call. Signed-off-by: Kumar Gala --- drivers/tty/serial/msm_serial.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/tty/serial/msm_serial.c b/drivers/tty/serial/msm_serial.c index 4b6c783..8ab27c9 100644 --- a/drivers/tty/serial/msm_serial.c +++ b/drivers/tty/serial/msm_serial.c @@ -973,6 +973,8 @@ msm_serial_early_console_setup(struct earlycon_device *device, const char *opt) if (!device->port.membase) return -ENODEV; + spin_lock_init(&device->port.lock); + device->con->write = msm_serial_early_write; return 0; } @@ -995,6 +997,8 @@ msm_serial_early_console_setup_dm(struct earlycon_device *device, if (!device->port.membase) return -ENODEV; + spin_lock_init(&device->port.lock); + device->con->write = msm_serial_early_write_dm; return 0; } -- Qualcomm Innovation Center, Inc. The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/