counter: 104-quad-8: Return error when invalid mode during ceiling_write

[ Upstream commit 728246e8f7269ecd35a2c6e6795323e6d8f48db7 ]

The 104-QUAD-8 only has two count modes where a ceiling value makes
sense: Range Limit and Modulo-N. Outside of these two modes, setting a
ceiling value is an invalid operation -- so let's report it as such by
returning -EINVAL.

Fixes: fc069262261c ("counter: 104-quad-8: Add lock guards - generic interface")
Acked-by: Syed Nayyar Waris <syednwaris@gmail.com>
Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com>
Link: https://lore.kernel.org/r/a2147f022829b66839a1db5530a7fada47856847.1627990337.git.vilhelm.gray@gmail.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/counter/104-quad-8.c b/drivers/counter/104-quad-8.c
index 78766b6ec271a3dc191cf1f4582c82c560e6ee73..21bb2bb767a1e2df61844f29e7012253eef2c595 100644 (file)
--- a/drivers/counter/104-quad-8.c
+++ b/drivers/counter/104-quad-8.c
@@ -1224,12 +1224,13 @@ static ssize_t quad8_count_ceiling_write(struct counter_device *counter,
        case 1:
        case 3:
                quad8_preset_register_set(priv, count->id, ceiling);
-               break;
+               mutex_unlock(&priv->lock);
+               return len;
        }
 
        mutex_unlock(&priv->lock);
 
-       return len;
+       return -EINVAL;
 }
 
 static ssize_t quad8_count_preset_enable_read(struct counter_device *counter,