From 29f020290d8897e3ed6ed8a8f8938c0b8545bbcd Mon Sep 17 00:00:00 2001
From: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
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 <bryan.odonoghue@linaro.org>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
---
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 33c21cf22687..7e1f527e3aef 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;
--
2.30.2