android_kernel_xiaomi_sm8350/drivers/firewire/fw-device.c
Stefan Richter 855c603d61 firewire: fix crash in automatic module unloading
"modprobe firewire-ohci; sleep .1; modprobe -r firewire-ohci" used to
result in crashes like this:

    BUG: unable to handle kernel paging request at ffffffff8807b455
    IP: [<ffffffff8807b455>]
    PGD 203067 PUD 207063 PMD 7c170067 PTE 0
    Oops: 0010 [1] PREEMPT SMP
    CPU 0
    Modules linked in: i915 drm cpufreq_ondemand acpi_cpufreq freq_table applesmc input_polldev led_class coretemp hwmon eeprom snd_seq_oss snd_seq_midi_event snd_seq snd_seq_device snd_pcm_oss snd_mixer_oss button thermal processor sg snd_hda_intel snd_pcm snd_timer snd snd_page_alloc sky2 i2c_i801 rtc [last unloaded: crc_itu_t]
    Pid: 9, comm: events/0 Not tainted 2.6.25-rc2 #3
    RIP: 0010:[<ffffffff8807b455>]  [<ffffffff8807b455>]
    RSP: 0018:ffff81007dcdde88  EFLAGS: 00010246
    RAX: ffff81007dc95040 RBX: ffff81007dee5390 RCX: 0000000000005e13
    RDX: 0000000000008c8b RSI: 0000000000000001 RDI: ffff81007dee5388
    RBP: ffff81007dc5eb40 R08: 0000000000000002 R09: ffffffff8022d05c
    R10: ffffffff8023b34c R11: ffffffff8041a353 R12: ffff81007dee5388
    R13: ffffffff8807b455 R14: ffffffff80593bc0 R15: 0000000000000000
    FS:  0000000000000000(0000) GS:ffffffff8055a000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0018 ES: 0018 CR0: 000000008005003b
    CR2: ffffffff8807b455 CR3: 0000000000201000 CR4: 00000000000006e0
    DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
    DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
    Process events/0 (pid: 9, threadinfo ffff81007dcdc000, task ffff81007dc95040)
    Stack:  ffffffff8023b396 ffffffff88082524 0000000000000000 ffffffff8807d9ae
    ffff81007dc5eb40 ffff81007dc9dce0 ffff81007dc5eb40 ffff81007dc5eb80
    ffff81007dc9dce0 ffffffffffffffff ffffffff8023be87 0000000000000000
    Call Trace:
    [<ffffffff8023b396>] ? run_workqueue+0xdf/0x1df
    [<ffffffff8023be87>] ? worker_thread+0xd8/0xe3
    [<ffffffff8023e917>] ? autoremove_wake_function+0x0/0x2e
    [<ffffffff8023bdaf>] ? worker_thread+0x0/0xe3
    [<ffffffff8023e813>] ? kthread+0x47/0x74
    [<ffffffff804198e0>] ? trace_hardirqs_on_thunk+0x35/0x3a
    [<ffffffff8020c008>] ? child_rip+0xa/0x12
    [<ffffffff8020b6e3>] ? restore_args+0x0/0x3d
    [<ffffffff8023e68a>] ? kthreadd+0x14c/0x171
    [<ffffffff8023e68a>] ? kthreadd+0x14c/0x171
    [<ffffffff8023e7cc>] ? kthread+0x0/0x74
    [<ffffffff8020bffe>] ? child_rip+0x0/0x12

    Code:  Bad RIP value.
    RIP  [<ffffffff8807b455>]
    RSP <ffff81007dcdde88>
    CR2: ffffffff8807b455
    ---[ end trace c7366c6657fe5bed ]---

Note that this crash happened _after_ firewire-core was unloaded.  The
shared workqueue tried to run firewire-core's device initialization jobs
or similar jobs.

The fix makes sure that firewire-ohci and hence firewire-core is not
unloaded before all device shutdown jobs have been completed.  This is
determined by the count of device initializations minus device releases.

Also skip useless retries in the node initialization job if the node is
to be shut down.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
2008-03-02 12:35:46 +01:00

862 lines
22 KiB
C

/*
* Device probing and sysfs code.
*
* Copyright (C) 2005-2006 Kristian Hoegsberg <krh@bitplanet.net>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/module.h>
#include <linux/wait.h>
#include <linux/errno.h>
#include <linux/kthread.h>
#include <linux/device.h>
#include <linux/delay.h>
#include <linux/idr.h>
#include <linux/rwsem.h>
#include <asm/semaphore.h>
#include <asm/system.h>
#include <linux/ctype.h>
#include "fw-transaction.h"
#include "fw-topology.h"
#include "fw-device.h"
void fw_csr_iterator_init(struct fw_csr_iterator *ci, u32 * p)
{
ci->p = p + 1;
ci->end = ci->p + (p[0] >> 16);
}
EXPORT_SYMBOL(fw_csr_iterator_init);
int fw_csr_iterator_next(struct fw_csr_iterator *ci, int *key, int *value)
{
*key = *ci->p >> 24;
*value = *ci->p & 0xffffff;
return ci->p++ < ci->end;
}
EXPORT_SYMBOL(fw_csr_iterator_next);
static int is_fw_unit(struct device *dev);
static int match_unit_directory(u32 * directory, const struct fw_device_id *id)
{
struct fw_csr_iterator ci;
int key, value, match;
match = 0;
fw_csr_iterator_init(&ci, directory);
while (fw_csr_iterator_next(&ci, &key, &value)) {
if (key == CSR_VENDOR && value == id->vendor)
match |= FW_MATCH_VENDOR;
if (key == CSR_MODEL && value == id->model)
match |= FW_MATCH_MODEL;
if (key == CSR_SPECIFIER_ID && value == id->specifier_id)
match |= FW_MATCH_SPECIFIER_ID;
if (key == CSR_VERSION && value == id->version)
match |= FW_MATCH_VERSION;
}
return (match & id->match_flags) == id->match_flags;
}
static int fw_unit_match(struct device *dev, struct device_driver *drv)
{
struct fw_unit *unit = fw_unit(dev);
struct fw_driver *driver = fw_driver(drv);
int i;
/* We only allow binding to fw_units. */
if (!is_fw_unit(dev))
return 0;
for (i = 0; driver->id_table[i].match_flags != 0; i++) {
if (match_unit_directory(unit->directory, &driver->id_table[i]))
return 1;
}
return 0;
}
static int get_modalias(struct fw_unit *unit, char *buffer, size_t buffer_size)
{
struct fw_device *device = fw_device(unit->device.parent);
struct fw_csr_iterator ci;
int key, value;
int vendor = 0;
int model = 0;
int specifier_id = 0;
int version = 0;
fw_csr_iterator_init(&ci, &device->config_rom[5]);
while (fw_csr_iterator_next(&ci, &key, &value)) {
switch (key) {
case CSR_VENDOR:
vendor = value;
break;
case CSR_MODEL:
model = value;
break;
}
}
fw_csr_iterator_init(&ci, unit->directory);
while (fw_csr_iterator_next(&ci, &key, &value)) {
switch (key) {
case CSR_SPECIFIER_ID:
specifier_id = value;
break;
case CSR_VERSION:
version = value;
break;
}
}
return snprintf(buffer, buffer_size,
"ieee1394:ven%08Xmo%08Xsp%08Xver%08X",
vendor, model, specifier_id, version);
}
static int
fw_unit_uevent(struct device *dev, struct kobj_uevent_env *env)
{
struct fw_unit *unit = fw_unit(dev);
char modalias[64];
get_modalias(unit, modalias, sizeof(modalias));
if (add_uevent_var(env, "MODALIAS=%s", modalias))
return -ENOMEM;
return 0;
}
struct bus_type fw_bus_type = {
.name = "firewire",
.match = fw_unit_match,
};
EXPORT_SYMBOL(fw_bus_type);
static void fw_device_release(struct device *dev)
{
struct fw_device *device = fw_device(dev);
struct fw_card *card = device->card;
unsigned long flags;
/*
* Take the card lock so we don't set this to NULL while a
* FW_NODE_UPDATED callback is being handled.
*/
spin_lock_irqsave(&device->card->lock, flags);
device->node->data = NULL;
spin_unlock_irqrestore(&device->card->lock, flags);
fw_node_put(device->node);
kfree(device->config_rom);
kfree(device);
atomic_dec(&card->device_count);
}
int fw_device_enable_phys_dma(struct fw_device *device)
{
int generation = device->generation;
/* device->node_id, accessed below, must not be older than generation */
smp_rmb();
return device->card->driver->enable_phys_dma(device->card,
device->node_id,
generation);
}
EXPORT_SYMBOL(fw_device_enable_phys_dma);
struct config_rom_attribute {
struct device_attribute attr;
u32 key;
};
static ssize_t
show_immediate(struct device *dev, struct device_attribute *dattr, char *buf)
{
struct config_rom_attribute *attr =
container_of(dattr, struct config_rom_attribute, attr);
struct fw_csr_iterator ci;
u32 *dir;
int key, value;
if (is_fw_unit(dev))
dir = fw_unit(dev)->directory;
else
dir = fw_device(dev)->config_rom + 5;
fw_csr_iterator_init(&ci, dir);
while (fw_csr_iterator_next(&ci, &key, &value))
if (attr->key == key)
return snprintf(buf, buf ? PAGE_SIZE : 0,
"0x%06x\n", value);
return -ENOENT;
}
#define IMMEDIATE_ATTR(name, key) \
{ __ATTR(name, S_IRUGO, show_immediate, NULL), key }
static ssize_t
show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf)
{
struct config_rom_attribute *attr =
container_of(dattr, struct config_rom_attribute, attr);
struct fw_csr_iterator ci;
u32 *dir, *block = NULL, *p, *end;
int length, key, value, last_key = 0;
char *b;
if (is_fw_unit(dev))
dir = fw_unit(dev)->directory;
else
dir = fw_device(dev)->config_rom + 5;
fw_csr_iterator_init(&ci, dir);
while (fw_csr_iterator_next(&ci, &key, &value)) {
if (attr->key == last_key &&
key == (CSR_DESCRIPTOR | CSR_LEAF))
block = ci.p - 1 + value;
last_key = key;
}
if (block == NULL)
return -ENOENT;
length = min(block[0] >> 16, 256U);
if (length < 3)
return -ENOENT;
if (block[1] != 0 || block[2] != 0)
/* Unknown encoding. */
return -ENOENT;
if (buf == NULL)
return length * 4;
b = buf;
end = &block[length + 1];
for (p = &block[3]; p < end; p++, b += 4)
* (u32 *) b = (__force u32) __cpu_to_be32(*p);
/* Strip trailing whitespace and add newline. */
while (b--, (isspace(*b) || *b == '\0') && b > buf);
strcpy(b + 1, "\n");
return b + 2 - buf;
}
#define TEXT_LEAF_ATTR(name, key) \
{ __ATTR(name, S_IRUGO, show_text_leaf, NULL), key }
static struct config_rom_attribute config_rom_attributes[] = {
IMMEDIATE_ATTR(vendor, CSR_VENDOR),
IMMEDIATE_ATTR(hardware_version, CSR_HARDWARE_VERSION),
IMMEDIATE_ATTR(specifier_id, CSR_SPECIFIER_ID),
IMMEDIATE_ATTR(version, CSR_VERSION),
IMMEDIATE_ATTR(model, CSR_MODEL),
TEXT_LEAF_ATTR(vendor_name, CSR_VENDOR),
TEXT_LEAF_ATTR(model_name, CSR_MODEL),
TEXT_LEAF_ATTR(hardware_version_name, CSR_HARDWARE_VERSION),
};
static void
init_fw_attribute_group(struct device *dev,
struct device_attribute *attrs,
struct fw_attribute_group *group)
{
struct device_attribute *attr;
int i, j;
for (j = 0; attrs[j].attr.name != NULL; j++)
group->attrs[j] = &attrs[j].attr;
for (i = 0; i < ARRAY_SIZE(config_rom_attributes); i++) {
attr = &config_rom_attributes[i].attr;
if (attr->show(dev, attr, NULL) < 0)
continue;
group->attrs[j++] = &attr->attr;
}
BUG_ON(j >= ARRAY_SIZE(group->attrs));
group->attrs[j++] = NULL;
group->groups[0] = &group->group;
group->groups[1] = NULL;
group->group.attrs = group->attrs;
dev->groups = group->groups;
}
static ssize_t
modalias_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct fw_unit *unit = fw_unit(dev);
int length;
length = get_modalias(unit, buf, PAGE_SIZE);
strcpy(buf + length, "\n");
return length + 1;
}
static ssize_t
rom_index_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct fw_device *device = fw_device(dev->parent);
struct fw_unit *unit = fw_unit(dev);
return snprintf(buf, PAGE_SIZE, "%d\n",
(int)(unit->directory - device->config_rom));
}
static struct device_attribute fw_unit_attributes[] = {
__ATTR_RO(modalias),
__ATTR_RO(rom_index),
__ATTR_NULL,
};
static ssize_t
config_rom_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct fw_device *device = fw_device(dev);
memcpy(buf, device->config_rom, device->config_rom_length * 4);
return device->config_rom_length * 4;
}
static ssize_t
guid_show(struct device *dev, struct device_attribute *attr, char *buf)
{
struct fw_device *device = fw_device(dev);
return snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",
device->config_rom[3], device->config_rom[4]);
}
static struct device_attribute fw_device_attributes[] = {
__ATTR_RO(config_rom),
__ATTR_RO(guid),
__ATTR_NULL,
};
struct read_quadlet_callback_data {
struct completion done;
int rcode;
u32 data;
};
static void
complete_transaction(struct fw_card *card, int rcode,
void *payload, size_t length, void *data)
{
struct read_quadlet_callback_data *callback_data = data;
if (rcode == RCODE_COMPLETE)
callback_data->data = be32_to_cpu(*(__be32 *)payload);
callback_data->rcode = rcode;
complete(&callback_data->done);
}
static int
read_rom(struct fw_device *device, int generation, int index, u32 *data)
{
struct read_quadlet_callback_data callback_data;
struct fw_transaction t;
u64 offset;
/* device->node_id, accessed below, must not be older than generation */
smp_rmb();
init_completion(&callback_data.done);
offset = 0xfffff0000400ULL + index * 4;
fw_send_request(device->card, &t, TCODE_READ_QUADLET_REQUEST,
device->node_id, generation, device->max_speed,
offset, NULL, 4, complete_transaction, &callback_data);
wait_for_completion(&callback_data.done);
*data = callback_data.data;
return callback_data.rcode;
}
/*
* Read the bus info block, perform a speed probe, and read all of the rest of
* the config ROM. We do all this with a cached bus generation. If the bus
* generation changes under us, read_bus_info_block will fail and get retried.
* It's better to start all over in this case because the node from which we
* are reading the ROM may have changed the ROM during the reset.
*/
static int read_bus_info_block(struct fw_device *device, int generation)
{
static u32 rom[256];
u32 stack[16], sp, key;
int i, end, length;
device->max_speed = SCODE_100;
/* First read the bus info block. */
for (i = 0; i < 5; i++) {
if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
return -1;
/*
* As per IEEE1212 7.2, during power-up, devices can
* reply with a 0 for the first quadlet of the config
* rom to indicate that they are booting (for example,
* if the firmware is on the disk of a external
* harddisk). In that case we just fail, and the
* retry mechanism will try again later.
*/
if (i == 0 && rom[i] == 0)
return -1;
}
device->max_speed = device->node->max_speed;
/*
* Determine the speed of
* - devices with link speed less than PHY speed,
* - devices with 1394b PHY (unless only connected to 1394a PHYs),
* - all devices if there are 1394b repeaters.
* Note, we cannot use the bus info block's link_spd as starting point
* because some buggy firmwares set it lower than necessary and because
* 1394-1995 nodes do not have the field.
*/
if ((rom[2] & 0x7) < device->max_speed ||
device->max_speed == SCODE_BETA ||
device->card->beta_repeaters_present) {
u32 dummy;
/* for S1600 and S3200 */
if (device->max_speed == SCODE_BETA)
device->max_speed = device->card->link_speed;
while (device->max_speed > SCODE_100) {
if (read_rom(device, generation, 0, &dummy) ==
RCODE_COMPLETE)
break;
device->max_speed--;
}
}
/*
* Now parse the config rom. The config rom is a recursive
* directory structure so we parse it using a stack of
* references to the blocks that make up the structure. We
* push a reference to the root directory on the stack to
* start things off.
*/
length = i;
sp = 0;
stack[sp++] = 0xc0000005;
while (sp > 0) {
/*
* Pop the next block reference of the stack. The
* lower 24 bits is the offset into the config rom,
* the upper 8 bits are the type of the reference the
* block.
*/
key = stack[--sp];
i = key & 0xffffff;
if (i >= ARRAY_SIZE(rom))
/*
* The reference points outside the standard
* config rom area, something's fishy.
*/
return -1;
/* Read header quadlet for the block to get the length. */
if (read_rom(device, generation, i, &rom[i]) != RCODE_COMPLETE)
return -1;
end = i + (rom[i] >> 16) + 1;
i++;
if (end > ARRAY_SIZE(rom))
/*
* This block extends outside standard config
* area (and the array we're reading it
* into). That's broken, so ignore this
* device.
*/
return -1;
/*
* Now read in the block. If this is a directory
* block, check the entries as we read them to see if
* it references another block, and push it in that case.
*/
while (i < end) {
if (read_rom(device, generation, i, &rom[i]) !=
RCODE_COMPLETE)
return -1;
if ((key >> 30) == 3 && (rom[i] >> 30) > 1 &&
sp < ARRAY_SIZE(stack))
stack[sp++] = i + rom[i];
i++;
}
if (length < i)
length = i;
}
device->config_rom = kmalloc(length * 4, GFP_KERNEL);
if (device->config_rom == NULL)
return -1;
memcpy(device->config_rom, rom, length * 4);
device->config_rom_length = length;
return 0;
}
static void fw_unit_release(struct device *dev)
{
struct fw_unit *unit = fw_unit(dev);
kfree(unit);
}
static struct device_type fw_unit_type = {
.uevent = fw_unit_uevent,
.release = fw_unit_release,
};
static int is_fw_unit(struct device *dev)
{
return dev->type == &fw_unit_type;
}
static void create_units(struct fw_device *device)
{
struct fw_csr_iterator ci;
struct fw_unit *unit;
int key, value, i;
i = 0;
fw_csr_iterator_init(&ci, &device->config_rom[5]);
while (fw_csr_iterator_next(&ci, &key, &value)) {
if (key != (CSR_UNIT | CSR_DIRECTORY))
continue;
/*
* Get the address of the unit directory and try to
* match the drivers id_tables against it.
*/
unit = kzalloc(sizeof(*unit), GFP_KERNEL);
if (unit == NULL) {
fw_error("failed to allocate memory for unit\n");
continue;
}
unit->directory = ci.p + value - 1;
unit->device.bus = &fw_bus_type;
unit->device.type = &fw_unit_type;
unit->device.parent = &device->device;
snprintf(unit->device.bus_id, sizeof(unit->device.bus_id),
"%s.%d", device->device.bus_id, i++);
init_fw_attribute_group(&unit->device,
fw_unit_attributes,
&unit->attribute_group);
if (device_register(&unit->device) < 0)
goto skip_unit;
continue;
skip_unit:
kfree(unit);
}
}
static int shutdown_unit(struct device *device, void *data)
{
device_unregister(device);
return 0;
}
static DECLARE_RWSEM(idr_rwsem);
static DEFINE_IDR(fw_device_idr);
int fw_cdev_major;
struct fw_device *fw_device_get_by_devt(dev_t devt)
{
struct fw_device *device;
down_read(&idr_rwsem);
device = idr_find(&fw_device_idr, MINOR(devt));
if (device)
fw_device_get(device);
up_read(&idr_rwsem);
return device;
}
static void fw_device_shutdown(struct work_struct *work)
{
struct fw_device *device =
container_of(work, struct fw_device, work.work);
int minor = MINOR(device->device.devt);
fw_device_cdev_remove(device);
device_for_each_child(&device->device, NULL, shutdown_unit);
device_unregister(&device->device);
down_write(&idr_rwsem);
idr_remove(&fw_device_idr, minor);
up_write(&idr_rwsem);
fw_device_put(device);
}
static struct device_type fw_device_type = {
.release = fw_device_release,
};
/*
* These defines control the retry behavior for reading the config
* rom. It shouldn't be necessary to tweak these; if the device
* doesn't respond to a config rom read within 10 seconds, it's not
* going to respond at all. As for the initial delay, a lot of
* devices will be able to respond within half a second after bus
* reset. On the other hand, it's not really worth being more
* aggressive than that, since it scales pretty well; if 10 devices
* are plugged in, they're all getting read within one second.
*/
#define MAX_RETRIES 10
#define RETRY_DELAY (3 * HZ)
#define INITIAL_DELAY (HZ / 2)
static void fw_device_init(struct work_struct *work)
{
struct fw_device *device =
container_of(work, struct fw_device, work.work);
int minor, err;
/*
* All failure paths here set node->data to NULL, so that we
* don't try to do device_for_each_child() on a kfree()'d
* device.
*/
if (read_bus_info_block(device, device->generation) < 0) {
if (device->config_rom_retries < MAX_RETRIES &&
atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {
device->config_rom_retries++;
schedule_delayed_work(&device->work, RETRY_DELAY);
} else {
fw_notify("giving up on config rom for node id %x\n",
device->node_id);
if (device->node == device->card->root_node)
schedule_delayed_work(&device->card->work, 0);
fw_device_release(&device->device);
}
return;
}
err = -ENOMEM;
fw_device_get(device);
down_write(&idr_rwsem);
if (idr_pre_get(&fw_device_idr, GFP_KERNEL))
err = idr_get_new(&fw_device_idr, device, &minor);
up_write(&idr_rwsem);
if (err < 0)
goto error;
device->device.bus = &fw_bus_type;
device->device.type = &fw_device_type;
device->device.parent = device->card->device;
device->device.devt = MKDEV(fw_cdev_major, minor);
snprintf(device->device.bus_id, sizeof(device->device.bus_id),
"fw%d", minor);
init_fw_attribute_group(&device->device,
fw_device_attributes,
&device->attribute_group);
if (device_add(&device->device)) {
fw_error("Failed to add device.\n");
goto error_with_cdev;
}
create_units(device);
/*
* Transition the device to running state. If it got pulled
* out from under us while we did the intialization work, we
* have to shut down the device again here. Normally, though,
* fw_node_event will be responsible for shutting it down when
* necessary. We have to use the atomic cmpxchg here to avoid
* racing with the FW_NODE_DESTROYED case in
* fw_node_event().
*/
if (atomic_cmpxchg(&device->state,
FW_DEVICE_INITIALIZING,
FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN) {
fw_device_shutdown(&device->work.work);
} else {
if (device->config_rom_retries)
fw_notify("created device %s: GUID %08x%08x, S%d00, "
"%d config ROM retries\n",
device->device.bus_id,
device->config_rom[3], device->config_rom[4],
1 << device->max_speed,
device->config_rom_retries);
else
fw_notify("created device %s: GUID %08x%08x, S%d00\n",
device->device.bus_id,
device->config_rom[3], device->config_rom[4],
1 << device->max_speed);
}
/*
* Reschedule the IRM work if we just finished reading the
* root node config rom. If this races with a bus reset we
* just end up running the IRM work a couple of extra times -
* pretty harmless.
*/
if (device->node == device->card->root_node)
schedule_delayed_work(&device->card->work, 0);
return;
error_with_cdev:
down_write(&idr_rwsem);
idr_remove(&fw_device_idr, minor);
up_write(&idr_rwsem);
error:
fw_device_put(device); /* fw_device_idr's reference */
put_device(&device->device); /* our reference */
}
static int update_unit(struct device *dev, void *data)
{
struct fw_unit *unit = fw_unit(dev);
struct fw_driver *driver = (struct fw_driver *)dev->driver;
if (is_fw_unit(dev) && driver != NULL && driver->update != NULL) {
down(&dev->sem);
driver->update(unit);
up(&dev->sem);
}
return 0;
}
static void fw_device_update(struct work_struct *work)
{
struct fw_device *device =
container_of(work, struct fw_device, work.work);
fw_device_cdev_update(device);
device_for_each_child(&device->device, NULL, update_unit);
}
void fw_node_event(struct fw_card *card, struct fw_node *node, int event)
{
struct fw_device *device;
switch (event) {
case FW_NODE_CREATED:
case FW_NODE_LINK_ON:
if (!node->link_on)
break;
device = kzalloc(sizeof(*device), GFP_ATOMIC);
if (device == NULL)
break;
/*
* Do minimal intialization of the device here, the
* rest will happen in fw_device_init(). We need the
* card and node so we can read the config rom and we
* need to do device_initialize() now so
* device_for_each_child() in FW_NODE_UPDATED is
* doesn't freak out.
*/
device_initialize(&device->device);
atomic_set(&device->state, FW_DEVICE_INITIALIZING);
atomic_inc(&card->device_count);
device->card = card;
device->node = fw_node_get(node);
device->node_id = node->node_id;
device->generation = card->generation;
INIT_LIST_HEAD(&device->client_list);
/*
* Set the node data to point back to this device so
* FW_NODE_UPDATED callbacks can update the node_id
* and generation for the device.
*/
node->data = device;
/*
* Many devices are slow to respond after bus resets,
* especially if they are bus powered and go through
* power-up after getting plugged in. We schedule the
* first config rom scan half a second after bus reset.
*/
INIT_DELAYED_WORK(&device->work, fw_device_init);
schedule_delayed_work(&device->work, INITIAL_DELAY);
break;
case FW_NODE_UPDATED:
if (!node->link_on || node->data == NULL)
break;
device = node->data;
device->node_id = node->node_id;
smp_wmb(); /* update node_id before generation */
device->generation = card->generation;
if (atomic_read(&device->state) == FW_DEVICE_RUNNING) {
PREPARE_DELAYED_WORK(&device->work, fw_device_update);
schedule_delayed_work(&device->work, 0);
}
break;
case FW_NODE_DESTROYED:
case FW_NODE_LINK_OFF:
if (!node->data)
break;
/*
* Destroy the device associated with the node. There
* are two cases here: either the device is fully
* initialized (FW_DEVICE_RUNNING) or we're in the
* process of reading its config rom
* (FW_DEVICE_INITIALIZING). If it is fully
* initialized we can reuse device->work to schedule a
* full fw_device_shutdown(). If not, there's work
* scheduled to read it's config rom, and we just put
* the device in shutdown state to have that code fail
* to create the device.
*/
device = node->data;
if (atomic_xchg(&device->state,
FW_DEVICE_SHUTDOWN) == FW_DEVICE_RUNNING) {
PREPARE_DELAYED_WORK(&device->work, fw_device_shutdown);
schedule_delayed_work(&device->work, 0);
}
break;
}
}