diff options
| author | Christian Vogel <vogelchr@vogel.cx> | 2021-01-13 22:50:18 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-01-20 20:50:21 +0300 |
| commit | e3fe0e89fec6965342434e7acae7ed6e6f021d08 (patch) | |
| tree | ce3f47455ff4baf31257df72968eac2445f27bbc /drivers/w1/masters | |
| parent | 48b7de6687f6ed597ef7162151f1c35469775545 (diff) | |
| download | linux-e3fe0e89fec6965342434e7acae7ed6e6f021d08.tar.xz | |
w1/masters/ds2490: queue up found IDs during scan
Queue up found IDs in a buffer and run the callback once for each found ID
at the end. This is necessary because we hold the bus_mutex during the
whole scan, and some of the "add-device" callbacks deadlock as they
themselves want to mutex_lock(bus_mutex).
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Signed-off-by: Christian Vogel <vogelchr@vogel.cx>
Link: https://lore.kernel.org/r/20210113195018.7498-3-vogelchr@vogel.cx
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/w1/masters')
| -rw-r--r-- | drivers/w1/masters/ds2490.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/drivers/w1/masters/ds2490.c b/drivers/w1/masters/ds2490.c index e17c8f70dcd0..cd8821580f71 100644 --- a/drivers/w1/masters/ds2490.c +++ b/drivers/w1/masters/ds2490.c @@ -688,12 +688,22 @@ static void ds9490r_search(void *data, struct w1_master *master, * packet size. */ const size_t bufsize = 2 * 64; - u64 *buf; + u64 *buf, *found_ids; buf = kmalloc(bufsize, GFP_KERNEL); if (!buf) return; + /* + * We are holding the bus mutex during the scan, but adding devices via the + * callback needs the bus to be unlocked. So we queue up found ids here. + */ + found_ids = kmalloc_array(master->max_slave_count, sizeof(u64), GFP_KERNEL); + if (!found_ids) { + kfree(buf); + return; + } + mutex_lock(&master->bus_mutex); /* address to start searching at */ @@ -729,13 +739,13 @@ static void ds9490r_search(void *data, struct w1_master *master, if (err < 0) break; for (i = 0; i < err/8; ++i) { - ++found; - if (found <= search_limit) - callback(master, buf[i]); + found_ids[found++] = buf[i]; /* can't know if there will be a discrepancy * value after until the next id */ - if (found == search_limit) + if (found == search_limit) { master->search_id = buf[i]; + break; + } } } @@ -759,9 +769,14 @@ 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); kfree(buf); + + for (i = 0; i < found; i++) /* run callback for all queued up IDs */ + callback(master, found_ids[i]); + kfree(found_ids); } #if 0 |