From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965132AbbFJOeJ (ORCPT ); Wed, 10 Jun 2015 10:34:09 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:35151 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964938AbbFJOeC (ORCPT ); Wed, 10 Jun 2015 10:34:02 -0400 From: Bartosz Golaszewski To: Linus Walleij , Alexandre Courbot Cc: linux-gpio , LKML , Patrick Titiano , Benoit Cousson , Bartosz Golaszewski Subject: [PATCH] gpiolib: unexport requested gpios on gpiochip removal Date: Wed, 10 Jun 2015 16:34:21 +0200 Message-Id: <1433946861-22371-1-git-send-email-bgolaszewski@baylibre.com> X-Mailer: git-send-email 2.1.4 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When a GPIO expander device is removed - e.g. via i2c-adapter new_device/delete_device interface - with some GPIOs still requested, gpiochip_remove() function will emit a warning but remove the chip anyway. If we then reinstantiate this device and try to export any of the GPIOs still requested on gpiochip deletion the following warning will be emitted: WARNING: CPU: 0 PID: 90 at fs/sysfs/dir.c:31 sysfs_warn_dup+0x58/0x78() sysfs: cannot create duplicate filename '/class/gpio/gpio504' Modules linked in: gpio_pca953x ipv6 CPU: 0 PID: 90 Comm: sh Not tainted 4.0.0 #1 Hardware name: Generic AM33XX (Flattened Device Tree) [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x84/0x9c) [] (dump_stack) from [] (warn_slowpath_common+0x7c/0xb8) [] (warn_slowpath_common) from [] (warn_slowpath_fmt+0x30/0x40) [] (warn_slowpath_fmt) from [] (sysfs_warn_dup+0x58/0x78) [] (sysfs_warn_dup) from [] (sysfs_do_create_link_sd.isra.2+0xb0/0xb8) [] (sysfs_do_create_link_sd.isra.2) from [] (device_add+0x1e4/0x510) [] (device_add) from [] (device_create_groups_vargs+0x9c/0xc0) [] (device_create_groups_vargs) from [] (device_create_with_groups+0x24/0x2c) [] (device_create_with_groups) from [] (gpiod_export+0xf8/0x224) [] (gpiod_export) from [] (export_store+0x50/0xd0) [] (export_store) from [] (class_attr_store+0x18/0x24) [] (class_attr_store) from [] (sysfs_kf_write+0x4c/0x50) [] (sysfs_kf_write) from [] (kernfs_fop_write+0xbc/0x1a4) [] (kernfs_fop_write) from [] (vfs_write+0xa4/0x1b0) [] (vfs_write) from [] (SyS_write+0x40/0x94) [] (SyS_write) from [] (ret_fast_syscall+0x0/0x4c) sysfs_do_create_link_sd() fails due to dangling links in /sys/class/gpio rendering these GPIOs unusable until reboot. Instead of warning the user, just silently unexport all requested GPIOs. Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 6bc612b..74a5e45 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -342,7 +342,7 @@ void gpiochip_remove(struct gpio_chip *chip) spin_lock_irqsave(&gpio_lock, flags); for (id = 0; id < chip->ngpio; id++) { if (test_bit(FLAG_REQUESTED, &chip->desc[id].flags)) - dev_crit(chip->dev, "REMOVING GPIOCHIP WITH GPIOS STILL REQUESTED\n"); + gpiod_unexport(&chip->desc[id]); } for (id = 0; id < chip->ngpio; id++) chip->desc[id].chip = NULL; -- 2.1.4