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 <[email protected]> Signed-off-by: Christian Vogel <[email protected]> --- drivers/w1/masters/ds2490.c | 25 ++++++++++++++++++++----- 1 file 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 -- 2.30.0
