linux/drivers/usb/wusbcore/mmc.c
David Vrabel 56968d0c1a wusb: whci-hcd shouldn't do ASL/PZL updates while channel is inactive
ASL/PZL updates while the WUSB channel is inactive (i.e., the PZL and
ASL are stopped) may not complete.  This causes hangs when removing the
whci-hcd module if a device is still connected (removing the device
does an endpoint_disable which results in an ASL update to remove the
qset).

If the WUSB channel is inactive the update can simply be skipped as the
WHC doesn't care about the state of the ASL/PZL.

Signed-off-by: David Vrabel <david.vrabel@csr.com>
2008-11-25 14:23:40 +00:00

285 lines
7.6 KiB
C

/*
* WUSB Wire Adapter: Control/Data Streaming Interface (WUSB[8])
* MMC (Microscheduled Management Command) handling
*
* Copyright (C) 2005-2006 Intel Corporation
* Inaky Perez-Gonzalez <inaky.perez-gonzalez@intel.com>
*
* 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, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
*
* WUIEs and MMC IEs...well, they are almost the same at the end. MMC
* IEs are Wireless USB IEs that go into the MMC period...[what is
* that? look in Design-overview.txt].
*
*
* This is a simple subsystem to keep track of which IEs are being
* sent by the host in the MMC period.
*
* For each WUIE we ask to send, we keep it in an array, so we can
* request its removal later, or replace the content. They are tracked
* by pointer, so be sure to use the same pointer if you want to
* remove it or update the contents.
*
* FIXME:
* - add timers that autoremove intervalled IEs?
*/
#include <linux/usb/wusb.h>
#include "wusbhc.h"
/* Initialize the MMCIEs handling mechanism */
int wusbhc_mmcie_create(struct wusbhc *wusbhc)
{
u8 mmcies = wusbhc->mmcies_max;
wusbhc->mmcie = kcalloc(mmcies, sizeof(wusbhc->mmcie[0]), GFP_KERNEL);
if (wusbhc->mmcie == NULL)
return -ENOMEM;
mutex_init(&wusbhc->mmcie_mutex);
return 0;
}
/* Release resources used by the MMCIEs handling mechanism */
void wusbhc_mmcie_destroy(struct wusbhc *wusbhc)
{
kfree(wusbhc->mmcie);
}
/*
* Add or replace an MMC Wireless USB IE.
*
* @interval: See WUSB1.0[8.5.3.1]
* @repeat_cnt: See WUSB1.0[8.5.3.1]
* @handle: See WUSB1.0[8.5.3.1]
* @wuie: Pointer to the header of the WUSB IE data to add.
* MUST BE allocated in a kmalloc buffer (no stack or
* vmalloc).
* THE CALLER ALWAYS OWNS THE POINTER (we don't free it
* on remove, we just forget about it).
* @returns: 0 if ok, < 0 errno code on error.
*
* Goes over the *whole* @wusbhc->mmcie array looking for (a) the
* first free spot and (b) if @wuie is already in the array (aka:
* transmitted in the MMCs) the spot were it is.
*
* If present, we "overwrite it" (update).
*
*
* NOTE: Need special ordering rules -- see below WUSB1.0 Table 7-38.
* The host uses the handle as the 'sort' index. We
* allocate the last one always for the WUIE_ID_HOST_INFO, and
* the rest, first come first serve in inverse order.
*
* Host software must make sure that it adds the other IEs in
* the right order... the host hardware is responsible for
* placing the WCTA IEs in the right place with the other IEs
* set by host software.
*
* NOTE: we can access wusbhc->wa_descr without locking because it is
* read only.
*/
int wusbhc_mmcie_set(struct wusbhc *wusbhc, u8 interval, u8 repeat_cnt,
struct wuie_hdr *wuie)
{
int result = -ENOBUFS;
unsigned handle, itr;
/* Search a handle, taking into account the ordering */
mutex_lock(&wusbhc->mmcie_mutex);
switch (wuie->bIEIdentifier) {
case WUIE_ID_HOST_INFO:
/* Always last */
handle = wusbhc->mmcies_max - 1;
break;
case WUIE_ID_ISOCH_DISCARD:
dev_err(wusbhc->dev, "Special ordering case for WUIE ID 0x%x "
"unimplemented\n", wuie->bIEIdentifier);
result = -ENOSYS;
goto error_unlock;
default:
/* search for it or find the last empty slot */
handle = ~0;
for (itr = 0; itr < wusbhc->mmcies_max - 1; itr++) {
if (wusbhc->mmcie[itr] == wuie) {
handle = itr;
break;
}
if (wusbhc->mmcie[itr] == NULL)
handle = itr;
}
if (handle == ~0)
goto error_unlock;
}
result = (wusbhc->mmcie_add)(wusbhc, interval, repeat_cnt, handle,
wuie);
if (result >= 0)
wusbhc->mmcie[handle] = wuie;
error_unlock:
mutex_unlock(&wusbhc->mmcie_mutex);
return result;
}
EXPORT_SYMBOL_GPL(wusbhc_mmcie_set);
/*
* Remove an MMC IE previously added with wusbhc_mmcie_set()
*
* @wuie Pointer used to add the WUIE
*/
void wusbhc_mmcie_rm(struct wusbhc *wusbhc, struct wuie_hdr *wuie)
{
int result;
unsigned handle, itr;
mutex_lock(&wusbhc->mmcie_mutex);
for (itr = 0; itr < wusbhc->mmcies_max; itr++) {
if (wusbhc->mmcie[itr] == wuie) {
handle = itr;
goto found;
}
}
mutex_unlock(&wusbhc->mmcie_mutex);
return;
found:
result = (wusbhc->mmcie_rm)(wusbhc, handle);
if (result == 0)
wusbhc->mmcie[itr] = NULL;
mutex_unlock(&wusbhc->mmcie_mutex);
}
EXPORT_SYMBOL_GPL(wusbhc_mmcie_rm);
static int wusbhc_mmc_start(struct wusbhc *wusbhc)
{
int ret;
mutex_lock(&wusbhc->mutex);
ret = wusbhc->start(wusbhc);
if (ret >= 0)
wusbhc->active = 1;
mutex_unlock(&wusbhc->mutex);
return ret;
}
static void wusbhc_mmc_stop(struct wusbhc *wusbhc)
{
mutex_lock(&wusbhc->mutex);
wusbhc->active = 0;
wusbhc->stop(wusbhc, WUSB_CHANNEL_STOP_DELAY_MS);
mutex_unlock(&wusbhc->mutex);
}
/*
* wusbhc_start - start transmitting MMCs and accepting connections
* @wusbhc: the HC to start
*
* Establishes a cluster reservation, enables device connections, and
* starts MMCs with appropriate DNTS parameters.
*/
int wusbhc_start(struct wusbhc *wusbhc)
{
int result;
struct device *dev = wusbhc->dev;
WARN_ON(wusbhc->wuie_host_info != NULL);
result = wusbhc_rsv_establish(wusbhc);
if (result < 0) {
dev_err(dev, "cannot establish cluster reservation: %d\n",
result);
goto error_rsv_establish;
}
result = wusbhc_devconnect_start(wusbhc);
if (result < 0) {
dev_err(dev, "error enabling device connections: %d\n", result);
goto error_devconnect_start;
}
result = wusbhc_sec_start(wusbhc);
if (result < 0) {
dev_err(dev, "error starting security in the HC: %d\n", result);
goto error_sec_start;
}
/* FIXME: the choice of the DNTS parameters is somewhat
* arbitrary */
result = wusbhc->set_num_dnts(wusbhc, 0, 15);
if (result < 0) {
dev_err(dev, "Cannot set DNTS parameters: %d\n", result);
goto error_set_num_dnts;
}
result = wusbhc_mmc_start(wusbhc);
if (result < 0) {
dev_err(dev, "error starting wusbch: %d\n", result);
goto error_wusbhc_start;
}
return 0;
error_wusbhc_start:
wusbhc_sec_stop(wusbhc);
error_set_num_dnts:
error_sec_start:
wusbhc_devconnect_stop(wusbhc);
error_devconnect_start:
wusbhc_rsv_terminate(wusbhc);
error_rsv_establish:
return result;
}
/*
* wusbhc_stop - stop transmitting MMCs
* @wusbhc: the HC to stop
*
* Stops the WUSB channel and removes the cluster reservation.
*/
void wusbhc_stop(struct wusbhc *wusbhc)
{
wusbhc_mmc_stop(wusbhc);
wusbhc_sec_stop(wusbhc);
wusbhc_devconnect_stop(wusbhc);
wusbhc_rsv_terminate(wusbhc);
}
/*
* Set/reset/update a new CHID
*
* Depending on the previous state of the MMCs, start, stop or change
* the sent MMC. This effectively switches the host controller on and
* off (radio wise).
*/
int wusbhc_chid_set(struct wusbhc *wusbhc, const struct wusb_ckhdid *chid)
{
int result = 0;
if (memcmp(chid, &wusb_ckhdid_zero, sizeof(chid)) == 0)
chid = NULL;
mutex_lock(&wusbhc->mutex);
if (chid) {
if (wusbhc->active) {
mutex_unlock(&wusbhc->mutex);
return -EBUSY;
}
wusbhc->chid = *chid;
}
mutex_unlock(&wusbhc->mutex);
if (chid)
result = uwb_radio_start(&wusbhc->pal);
else
uwb_radio_stop(&wusbhc->pal);
return result;
}
EXPORT_SYMBOL_GPL(wusbhc_chid_set);