mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-05 10:36:42 +07:00
a899575191
This patch fixes a race condition that caused the HWA_HC interface probe function to occasionally fail. The HWA_HC would attempt to register itself with the HWA_RC by searching for a uwb_rc class device with the same parent device ptr. If the probe function for the HWA_RC interface had yet to run, the uwb_rc class device would not have been created causing the look up to fail and the HWA_HC probe function to return an error causing the device to be unusable. The fix is for the HWA to delay registering with the HWA_RC until receiving the command from userspace to start the wireless channel. It is the responsibility of userspace to ensure that the uwb_rc class device has been created before starting the HWA channel. Signed-off-by: Thomas Pugliese <thomas.pugliese@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
102 lines
2.4 KiB
C
102 lines
2.4 KiB
C
/*
|
|
* UWB PAL support.
|
|
*
|
|
* Copyright (C) 2008 Cambridge Silicon Radio Ltd.
|
|
*
|
|
* This program is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU General Public License version
|
|
* 2 as published by the Free Software Foundation.
|
|
*
|
|
* This program is distributed in the hope that it will be useful,
|
|
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU General Public License
|
|
* along with this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
#include <linux/kernel.h>
|
|
#include <linux/debugfs.h>
|
|
#include <linux/uwb.h>
|
|
#include <linux/export.h>
|
|
|
|
#include "uwb-internal.h"
|
|
|
|
/**
|
|
* uwb_pal_init - initialize a UWB PAL
|
|
* @pal: the PAL to initialize
|
|
*/
|
|
void uwb_pal_init(struct uwb_pal *pal)
|
|
{
|
|
INIT_LIST_HEAD(&pal->node);
|
|
}
|
|
EXPORT_SYMBOL_GPL(uwb_pal_init);
|
|
|
|
/**
|
|
* uwb_pal_register - register a UWB PAL
|
|
* @pal: the PAL
|
|
*
|
|
* The PAL must be initialized with uwb_pal_init().
|
|
*/
|
|
int uwb_pal_register(struct uwb_pal *pal)
|
|
{
|
|
struct uwb_rc *rc = pal->rc;
|
|
int ret;
|
|
|
|
if (pal->device) {
|
|
/* create a link to the uwb_rc in the PAL device's directory. */
|
|
ret = sysfs_create_link(&pal->device->kobj,
|
|
&rc->uwb_dev.dev.kobj, "uwb_rc");
|
|
if (ret < 0)
|
|
return ret;
|
|
/* create a link to the PAL in the UWB device's directory. */
|
|
ret = sysfs_create_link(&rc->uwb_dev.dev.kobj,
|
|
&pal->device->kobj, pal->name);
|
|
if (ret < 0) {
|
|
sysfs_remove_link(&pal->device->kobj, "uwb_rc");
|
|
return ret;
|
|
}
|
|
}
|
|
|
|
pal->debugfs_dir = uwb_dbg_create_pal_dir(pal);
|
|
|
|
mutex_lock(&rc->uwb_dev.mutex);
|
|
list_add(&pal->node, &rc->pals);
|
|
mutex_unlock(&rc->uwb_dev.mutex);
|
|
|
|
return 0;
|
|
}
|
|
EXPORT_SYMBOL_GPL(uwb_pal_register);
|
|
|
|
/**
|
|
* uwb_pal_register - unregister a UWB PAL
|
|
* @pal: the PAL
|
|
*/
|
|
void uwb_pal_unregister(struct uwb_pal *pal)
|
|
{
|
|
struct uwb_rc *rc = pal->rc;
|
|
|
|
uwb_radio_stop(pal);
|
|
|
|
mutex_lock(&rc->uwb_dev.mutex);
|
|
list_del(&pal->node);
|
|
mutex_unlock(&rc->uwb_dev.mutex);
|
|
|
|
debugfs_remove(pal->debugfs_dir);
|
|
|
|
if (pal->device) {
|
|
sysfs_remove_link(&rc->uwb_dev.dev.kobj, pal->name);
|
|
sysfs_remove_link(&pal->device->kobj, "uwb_rc");
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(uwb_pal_unregister);
|
|
|
|
/**
|
|
* uwb_rc_pal_init - initialize the PAL related parts of a radio controller
|
|
* @rc: the radio controller
|
|
*/
|
|
void uwb_rc_pal_init(struct uwb_rc *rc)
|
|
{
|
|
INIT_LIST_HEAD(&rc->pals);
|
|
}
|