This makes it possible to enqueue frames also from atomic context which
is needed for example, when networking packets are sent over a
Thunderbolt cable.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Michael Jamet <michael.jamet@intel.com>
Reviewed-by: Yehezkel Bernat <yehezkel.bernat@intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
---
drivers/thunderbolt/nhi.c | 26 ++++++++++++++------------
include/linux/thunderbolt.h | 2 +-
2 files changed, 15 insertions(+), 13 deletions(-)

diff --git a/drivers/thunderbolt/nhi.c b/drivers/thunderbolt/nhi.c
index e0a47f7581cb..7d1891ec3c47 100644
--- a/drivers/thunderbolt/nhi.c
+++ b/drivers/thunderbolt/nhi.c
@@ -212,8 +212,10 @@ static void ring_work(struct work_struct *work)
struct tb_ring *ring = container_of(work, typeof(*ring), work);
struct ring_frame *frame;
bool canceled = false;
+ unsigned long flags;
LIST_HEAD(done);
- mutex_lock(&ring->lock);
+
+ spin_lock_irqsave(&ring->lock, flags);

if (!ring->running) {
/* Move all frames to done and mark them as canceled. */
@@ -241,7 +243,8 @@ static void ring_work(struct work_struct *work)
ring_write_descriptors(ring);

invoke_callback:
- mutex_unlock(&ring->lock); /* allow callbacks to schedule new work */
+ /* allow callbacks to schedule new work */
+ spin_unlock_irqrestore(&ring->lock, flags);