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w1: hold bus_mutex in netlink and search

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The bus_mutex needs to be taken to serialize access to a specific bus.
netlink wasn't updated when bus_mutex was added and was calling
without that lock held, and not all of the masters were holding the
bus_mutex in a search.  This was causing the ds2490 hardware to stop
responding when both netlink and /sys slaves were executing bus
commands at the same time.

Signed-off-by: David Fries <David@Fries.net>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
David Fries 2014-01-15 22:29:26 -06:00 • committed by Greg Kroah-Hartman
parent b3be177a19
commit d3a8a9dbb9
3 changed files with 20 additions and 5 deletions
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4
drivers/w1/masters/ds1wm.c
View file

@ -326,13 +326,14 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
unsigned slaves_found = 0; unsigned slaves_found = 0;
unsigned int pass = 0; unsigned int pass = 0;
mutex_lock(&master_dev->bus_mutex);
dev_dbg(&ds1wm_data->pdev->dev, "search begin\n"); dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
while (true) { while (true) {
++pass; ++pass;
if (pass > 100) { if (pass > 100) {
dev_dbg(&ds1wm_data->pdev->dev, dev_dbg(&ds1wm_data->pdev->dev,
"too many attempts (100), search aborted\n"); "too many attempts (100), search aborted\n");
return; break;
} }
mutex_lock(&master_dev->bus_mutex); mutex_lock(&master_dev->bus_mutex);
@ -439,6 +440,7 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
dev_dbg(&ds1wm_data->pdev->dev, dev_dbg(&ds1wm_data->pdev->dev,
"pass: %d total: %d search done ms d bit pos: %d\n", pass, "pass: %d total: %d search done ms d bit pos: %d\n", pass,
slaves_found, ms_discrep_bit); slaves_found, ms_discrep_bit);
mutex_unlock(&master_dev->bus_mutex);
} }
/* --------------------------------------------------------------------- */ /* --------------------------------------------------------------------- */

8
drivers/w1/masters/ds2490.c
View file

@ -727,9 +727,11 @@ static void ds9490r_search(void *data, struct w1_master *master,
*/ */
u64 buf[2*64/8]; u64 buf[2*64/8];
mutex_lock(&master->bus_mutex);
/* address to start searching at */ /* address to start searching at */
if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0) if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
return; goto search_out;
master->search_id = 0; master->search_id = 0;
value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F | value = COMM_SEARCH_ACCESS | COMM_IM | COMM_RST | COMM_SM | COMM_F |
@ -739,7 +741,7 @@ static void ds9490r_search(void *data, struct w1_master *master,
search_limit = 0; search_limit = 0;
index = search_type | (search_limit << 8); index = search_type | (search_limit << 8);
if (ds_send_control(dev, value, index) < 0) if (ds_send_control(dev, value, index) < 0)
return; goto search_out;
do { do {
schedule_timeout(jtime); schedule_timeout(jtime);
@ -791,6 +793,8 @@ static void ds9490r_search(void *data, struct w1_master *master,
master->max_slave_count); master->max_slave_count);
set_bit(W1_WARN_MAX_COUNT, &master->flags); set_bit(W1_WARN_MAX_COUNT, &master->flags);
} }
search_out:
mutex_unlock(&master->bus_mutex);
} }
#if 0 #if 0

13
drivers/w1/w1_netlink.c
View file

@ -246,11 +246,16 @@ static int w1_process_command_master(struct w1_master *dev,
{ {
int err = -EINVAL; int err = -EINVAL;
/* drop bus_mutex for search (does it's own locking), and add/remove
* which doesn't use the bus
*/
switch (req_cmd->cmd) { switch (req_cmd->cmd) {
case W1_CMD_SEARCH: case W1_CMD_SEARCH:
case W1_CMD_ALARM_SEARCH: case W1_CMD_ALARM_SEARCH:
case W1_CMD_LIST_SLAVES: case W1_CMD_LIST_SLAVES:
mutex_unlock(&dev->bus_mutex);
err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd); err = w1_get_slaves(dev, req_msg, req_hdr, req_cmd);
mutex_lock(&dev->bus_mutex);
break; break;
case W1_CMD_READ: case W1_CMD_READ:
case W1_CMD_WRITE: case W1_CMD_WRITE:
@ -262,8 +267,12 @@ static int w1_process_command_master(struct w1_master *dev,
break; break;
case W1_CMD_SLAVE_ADD: case W1_CMD_SLAVE_ADD:
case W1_CMD_SLAVE_REMOVE: case W1_CMD_SLAVE_REMOVE:
mutex_unlock(&dev->bus_mutex);
mutex_lock(&dev->mutex);
err = w1_process_command_addremove(dev, req_msg, req_hdr, err = w1_process_command_addremove(dev, req_msg, req_hdr,
req_cmd); req_cmd);
mutex_unlock(&dev->mutex);
mutex_lock(&dev->bus_mutex);
break; break;
default: default:
err = -EINVAL; err = -EINVAL;
@ -400,7 +409,7 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
struct w1_slave *sl = node->sl; struct w1_slave *sl = node->sl;
struct w1_netlink_cmd *cmd = NULL; struct w1_netlink_cmd *cmd = NULL;
mutex_lock(&dev->mutex); mutex_lock(&dev->bus_mutex);
dev->portid = node->block->portid; dev->portid = node->block->portid;
if (sl && w1_reset_select_slave(sl)) if (sl && w1_reset_select_slave(sl))
err = -ENODEV; err = -ENODEV;
@ -437,7 +446,7 @@ static void w1_process_cb(struct w1_master *dev, struct w1_async_cmd *async_cmd)
else else
atomic_dec(&dev->refcnt); atomic_dec(&dev->refcnt);
dev->portid = 0; dev->portid = 0;
mutex_unlock(&dev->mutex); mutex_unlock(&dev->bus_mutex);
mutex_lock(&dev->list_mutex); mutex_lock(&dev->list_mutex);
list_del(&async_cmd->async_entry); list_del(&async_cmd->async_entry);