Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753914AbdFSJ1Z (ORCPT ); Mon, 19 Jun 2017 05:27:25 -0400 Received: from ozlabs.org ([103.22.144.67]:41971 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752339AbdFSJ1V (ORCPT ); Mon, 19 Jun 2017 05:27:21 -0400 From: Jeremy Kerr To: linux-kernel@vger.kernel.org Cc: Joel Stanley , Christopher Bostic , Jeremy Kerr Subject: [PATCH 2/3] fsi/master-gpio: Add locking around gpio operations during break & link enable Date: Mon, 19 Jun 2017 17:26:44 +0800 Message-Id: <1497864405-26990-3-git-send-email-jk@ozlabs.org> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1497864405-26990-1-git-send-email-jk@ozlabs.org> References: <1497864405-26990-1-git-send-email-jk@ozlabs.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1792 Lines: 55 Currently, we perform GPIO accesses in fsi_master_gpio_break and fsi_master_link_enable, without holding cmd_lock. This change adds the appropriate locking. Signed-off-by: Jeremy Kerr Reviewed-by: Joel Stanley Reviewed-by: Christopher Bostic --- drivers/fsi/fsi-master-gpio.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/fsi/fsi-master-gpio.c b/drivers/fsi/fsi-master-gpio.c index ae26187..a6d602e 100644 --- a/drivers/fsi/fsi-master-gpio.c +++ b/drivers/fsi/fsi-master-gpio.c @@ -461,12 +461,14 @@ static int fsi_master_gpio_term(struct fsi_master *_master, static int fsi_master_gpio_break(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + unsigned long flags; if (link != 0) return -ENODEV; trace_fsi_master_gpio_break(master); + spin_lock_irqsave(&master->cmd_lock, flags); set_sda_output(master, 1); sda_out(master, 1); clock_toggle(master, FSI_PRE_BREAK_CLOCKS); @@ -475,6 +477,7 @@ static int fsi_master_gpio_break(struct fsi_master *_master, int link) echo_delay(master); sda_out(master, 1); clock_toggle(master, FSI_POST_BREAK_CLOCKS); + spin_unlock_irqrestore(&master->cmd_lock, flags); /* Wait for logic reset to take effect */ udelay(200); @@ -497,10 +500,14 @@ static void fsi_master_gpio_init(struct fsi_master_gpio *master) static int fsi_master_gpio_link_enable(struct fsi_master *_master, int link) { struct fsi_master_gpio *master = to_fsi_master_gpio(_master); + unsigned long flags; if (link != 0) return -ENODEV; + + spin_lock_irqsave(&master->cmd_lock, flags); gpiod_set_value(master->gpio_enable, 1); + spin_unlock_irqrestore(&master->cmd_lock, flags); return 0; } -- 2.7.4