From 29f020290d8897e3ed6ed8a8f8938c0b8545bbcd Mon Sep 17 00:00:00 2001 From: Bryan O'Donoghue Date: Mon, 14 Sep 2015 10:48:40 +0100 Subject: [PATCH] greybus: loopback: hold a coarse lock while init/exit run This patch holds gb_dev.mutex for the duration of init and exit to reduce complexity while ensuring that init and exit run atomically with respect to slave threads @ gb_loopback_fn(). Signed-off-by: Bryan O'Donoghue Reviewed-by: Viresh Kumar Signed-off-by: Greg Kroah-Hartman --- drivers/staging/greybus/loopback.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-) diff --git a/drivers/staging/greybus/loopback.c b/drivers/staging/greybus/loopback.c index 33c21cf..7e1f527 100644 --- a/drivers/staging/greybus/loopback.c +++ b/drivers/staging/greybus/loopback.c @@ -864,21 +864,18 @@ static int gb_loopback_connection_init(struct gb_connection *connection) gb_dev.root, &gb_dev, &gb_loopback_debugfs_dev_latency_ops); retval = sysfs_create_groups(kobj, loopback_dev_groups); - if (retval) { - mutex_unlock(&gb_dev.mutex); + if (retval) goto out_sysfs; - } + /* Calculate maximum payload */ gb_dev.size_max = gb_operation_get_payload_size_max(connection); if (gb_dev.size_max <= sizeof(struct gb_loopback_transfer_request)) { retval = -EINVAL; - mutex_unlock(&gb_dev.mutex); goto out_sysfs; } gb_dev.size_max -= sizeof(struct gb_loopback_transfer_request); } - mutex_unlock(&gb_dev.mutex); /* Create per-connection sysfs and debugfs data-points */ snprintf(name, sizeof(name), "raw_latency_endo0:%d:%d:%d:%d", @@ -916,10 +913,9 @@ static int gb_loopback_connection_init(struct gb_connection *connection) goto out_kfifo1; } - mutex_lock(&gb_dev.mutex); list_add_tail(&gb->entry, &gb_dev.list); - mutex_unlock(&gb_dev.mutex); gb_dev.count++; + mutex_unlock(&gb_dev.mutex); return 0; out_kfifo1: @@ -934,6 +930,7 @@ out_sysfs_dev: debugfs_remove(gb->file); connection->private = NULL; out_sysfs: + mutex_unlock(&gb_dev.mutex); kfree(gb); return retval; -- 2.7.4