w1: hold bus_mutex in netlink and search
authorDavid Fries <David@Fries.net>
Thu, 16 Jan 2014 04:29:26 +0000 (22:29 -0600)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 7 Feb 2014 23:40:18 +0000 (15:40 -0800)
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>
drivers/w1/masters/ds1wm.c
drivers/w1/masters/ds2490.c
drivers/w1/w1_netlink.c

index 02df3b1..b077b8b 100644 (file)
@@ -326,13 +326,14 @@ static void ds1wm_search(void *data, struct w1_master *master_dev,
        unsigned slaves_found = 0;
        unsigned int pass = 0;
 
+       mutex_lock(&master_dev->bus_mutex);
        dev_dbg(&ds1wm_data->pdev->dev, "search begin\n");
        while (true) {
                ++pass;
                if (pass > 100) {
                        dev_dbg(&ds1wm_data->pdev->dev,
                                "too many attempts (100), search aborted\n");
-                       return;
+                       break;
                }
 
                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,
                "pass: %d total: %d search done ms d bit pos: %d\n", pass,
                slaves_found, ms_discrep_bit);
+       mutex_unlock(&master_dev->bus_mutex);
 }
 
 /* --------------------------------------------------------------------- */
index db0bf32..7404ad3 100644 (file)
@@ -727,9 +727,11 @@ static void ds9490r_search(void *data, struct w1_master *master,
         */
        u64 buf[2*64/8];
 
+       mutex_lock(&master->bus_mutex);
+
        /* address to start searching at */
        if (ds_send_data(dev, (u8 *)&master->search_id, 8) < 0)
-               return;
+               goto search_out;
        master->search_id = 0;
 
        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;
        index = search_type | (search_limit << 8);
        if (ds_send_control(dev, value, index) < 0)
-               return;
+               goto search_out;
 
        do {
                schedule_timeout(jtime);
@@ -791,6 +793,8 @@ static void ds9490r_search(void *data, struct w1_master *master,
                        master->max_slave_count);
                set_bit(W1_WARN_MAX_COUNT, &master->flags);
        }
+search_out:
+       mutex_unlock(&master->bus_mutex);
 }
 
 #if 0
Simple merge