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d6124b409c
This subsystem consistently fails to drop the device reference taken by
class_find_device().
Note that some of these lookup functions already take a reference to the
returned data, while others claim no reference is needed (or does not
seem need one).
Fixes: 183b9b592a ("uwb: add the UWB stack (core files)")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
140 lines
3.2 KiB
C
140 lines
3.2 KiB
C
/*
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* UWB PAL support.
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*
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* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License version
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* 2 as published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <linux/kernel.h>
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#include <linux/debugfs.h>
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#include <linux/uwb.h>
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#include <linux/export.h>
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#include "uwb-internal.h"
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/**
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* uwb_pal_init - initialize a UWB PAL
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* @pal: the PAL to initialize
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*/
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void uwb_pal_init(struct uwb_pal *pal)
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{
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INIT_LIST_HEAD(&pal->node);
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}
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EXPORT_SYMBOL_GPL(uwb_pal_init);
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/**
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* uwb_pal_register - register a UWB PAL
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* @pal: the PAL
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*
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* The PAL must be initialized with uwb_pal_init().
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*/
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int uwb_pal_register(struct uwb_pal *pal)
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{
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struct uwb_rc *rc = pal->rc;
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int ret;
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if (pal->device) {
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/* create a link to the uwb_rc in the PAL device's directory. */
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ret = sysfs_create_link(&pal->device->kobj,
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&rc->uwb_dev.dev.kobj, "uwb_rc");
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if (ret < 0)
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return ret;
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/* create a link to the PAL in the UWB device's directory. */
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ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
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&pal->device->kobj, pal->name);
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if (ret < 0) {
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sysfs_remove_link(&pal->device->kobj, "uwb_rc");
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return ret;
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}
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}
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pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);
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mutex_lock(&rc->uwb_dev.mutex);
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list_add(&pal->node, &rc->pals);
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mutex_unlock(&rc->uwb_dev.mutex);
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return 0;
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}
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EXPORT_SYMBOL_GPL(uwb_pal_register);
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static int find_rc(struct device *dev, const void *data)
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{
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const struct uwb_rc *target_rc = data;
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struct uwb_rc *rc = dev_get_drvdata(dev);
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if (rc == NULL) {
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WARN_ON(1);
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return 0;
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}
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if (rc == target_rc) {
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if (rc->ready == 0)
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return 0;
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else
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return 1;
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}
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return 0;
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}
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/**
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* Given a radio controller descriptor see if it is registered.
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*
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* @returns false if the rc does not exist or is quiescing; true otherwise.
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*/
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static bool uwb_rc_class_device_exists(struct uwb_rc *target_rc)
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{
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struct device *dev;
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dev = class_find_device(&uwb_rc_class, NULL, target_rc, find_rc);
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put_device(dev);
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return (dev != NULL);
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}
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/**
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* uwb_pal_unregister - unregister a UWB PAL
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* @pal: the PAL
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*/
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void uwb_pal_unregister(struct uwb_pal *pal)
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{
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struct uwb_rc *rc = pal->rc;
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uwb_radio_stop(pal);
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mutex_lock(&rc->uwb_dev.mutex);
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list_del(&pal->node);
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mutex_unlock(&rc->uwb_dev.mutex);
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debugfs_remove(pal->debugfs_dir);
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if (pal->device) {
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/* remove link to the PAL in the UWB device's directory. */
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if (uwb_rc_class_device_exists(rc))
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sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
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/* remove link to uwb_rc in the PAL device's directory. */
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sysfs_remove_link(&pal->device->kobj, "uwb_rc");
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}
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}
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EXPORT_SYMBOL_GPL(uwb_pal_unregister);
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/**
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* uwb_rc_pal_init - initialize the PAL related parts of a radio controller
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* @rc: the radio controller
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*/
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void uwb_rc_pal_init(struct uwb_rc *rc)
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{
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INIT_LIST_HEAD(&rc->pals);
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}
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