mirror of
https://github.com/edk2-porting/linux-next.git
synced 2024-12-21 11:44:01 +08:00
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>
122 lines
3.1 KiB
C
122 lines
3.1 KiB
C
/*
|
|
* WUSB cluster reservation management
|
|
*
|
|
* Copyright (C) 2007 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/uwb.h>
|
|
|
|
#include "wusbhc.h"
|
|
|
|
/*
|
|
* WUSB cluster reservations are multicast reservations with the
|
|
* broadcast cluster ID (BCID) as the target DevAddr.
|
|
*
|
|
* FIXME: consider adjusting the reservation depending on what devices
|
|
* are attached.
|
|
*/
|
|
|
|
static int wusbhc_bwa_set(struct wusbhc *wusbhc, u8 stream,
|
|
const struct uwb_mas_bm *mas)
|
|
{
|
|
if (mas == NULL)
|
|
mas = &uwb_mas_bm_zero;
|
|
return wusbhc->bwa_set(wusbhc, stream, mas);
|
|
}
|
|
|
|
/**
|
|
* wusbhc_rsv_complete_cb - WUSB HC reservation complete callback
|
|
* @rsv: the reservation
|
|
*
|
|
* Either set or clear the HC's view of the reservation.
|
|
*
|
|
* FIXME: when a reservation is denied the HC should be stopped.
|
|
*/
|
|
static void wusbhc_rsv_complete_cb(struct uwb_rsv *rsv)
|
|
{
|
|
struct wusbhc *wusbhc = rsv->pal_priv;
|
|
struct device *dev = wusbhc->dev;
|
|
struct uwb_mas_bm mas;
|
|
char buf[72];
|
|
|
|
switch (rsv->state) {
|
|
case UWB_RSV_STATE_O_ESTABLISHED:
|
|
uwb_rsv_get_usable_mas(rsv, &mas);
|
|
bitmap_scnprintf(buf, sizeof(buf), mas.bm, UWB_NUM_MAS);
|
|
dev_dbg(dev, "established reservation: %s\n", buf);
|
|
wusbhc_bwa_set(wusbhc, rsv->stream, &mas);
|
|
break;
|
|
case UWB_RSV_STATE_NONE:
|
|
dev_dbg(dev, "removed reservation\n");
|
|
wusbhc_bwa_set(wusbhc, 0, NULL);
|
|
break;
|
|
default:
|
|
dev_dbg(dev, "unexpected reservation state: %d\n", rsv->state);
|
|
break;
|
|
}
|
|
}
|
|
|
|
|
|
/**
|
|
* wusbhc_rsv_establish - establish a reservation for the cluster
|
|
* @wusbhc: the WUSB HC requesting a bandwidth reservation
|
|
*/
|
|
int wusbhc_rsv_establish(struct wusbhc *wusbhc)
|
|
{
|
|
struct uwb_rc *rc = wusbhc->uwb_rc;
|
|
struct uwb_rsv *rsv;
|
|
struct uwb_dev_addr bcid;
|
|
int ret;
|
|
|
|
if (rc == NULL)
|
|
return -ENODEV;
|
|
|
|
rsv = uwb_rsv_create(rc, wusbhc_rsv_complete_cb, wusbhc);
|
|
if (rsv == NULL)
|
|
return -ENOMEM;
|
|
|
|
bcid.data[0] = wusbhc->cluster_id;
|
|
bcid.data[1] = 0;
|
|
|
|
rsv->target.type = UWB_RSV_TARGET_DEVADDR;
|
|
rsv->target.devaddr = bcid;
|
|
rsv->type = UWB_DRP_TYPE_PRIVATE;
|
|
rsv->max_mas = 256; /* try to get as much as possible */
|
|
rsv->min_mas = 15; /* one MAS per zone */
|
|
rsv->max_interval = 1; /* max latency is one zone */
|
|
rsv->is_multicast = true;
|
|
|
|
ret = uwb_rsv_establish(rsv);
|
|
if (ret == 0)
|
|
wusbhc->rsv = rsv;
|
|
else
|
|
uwb_rsv_destroy(rsv);
|
|
return ret;
|
|
}
|
|
|
|
|
|
/**
|
|
* wusbhc_rsv_terminate - terminate the cluster reservation
|
|
* @wusbhc: the WUSB host whose reservation is to be terminated
|
|
*/
|
|
void wusbhc_rsv_terminate(struct wusbhc *wusbhc)
|
|
{
|
|
if (wusbhc->rsv) {
|
|
uwb_rsv_terminate(wusbhc->rsv);
|
|
uwb_rsv_destroy(wusbhc->rsv);
|
|
wusbhc->rsv = NULL;
|
|
}
|
|
}
|