On 05/06/2018 13:38, Cornelia Huck wrote:
On Fri, 25 May 2018 12:21:14 +0200
Pierre Morel <pmorel@xxxxxxxxxxxxxxxxxx> wrote:
We use mutex around the FSM function call to make the FSM
event handling and state change atomic.
I'm still not really clear as to what this mutex is supposed to
serialize:
- Modification of the state?
- Any calls in the state machine?
- A combination? (That would imply that we only deal with the state in
the state machine.)
yes to all
Signed-off-by: Pierre Morel <pmorel@xxxxxxxxxxxxxxxxxx>
---
drivers/s390/cio/vfio_ccw_drv.c | 3 +--
drivers/s390/cio/vfio_ccw_private.h | 3 +++
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/s390/cio/vfio_ccw_drv.c b/drivers/s390/cio/vfio_ccw_drv.c
index 6b7112e..98951d5 100644
--- a/drivers/s390/cio/vfio_ccw_drv.c
+++ b/drivers/s390/cio/vfio_ccw_drv.c
@@ -73,8 +73,6 @@ static void vfio_ccw_sch_io_todo(struct work_struct *work)
private = container_of(work, struct vfio_ccw_private, io_work);
vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_INTERRUPT);
- if (private->mdev)
- private->state = VFIO_CCW_STATE_IDLE;
Looks like an unrelated change? If you want to do all state changes
under the mutex, that should rather be moved than deleted, shouldn't it?
It is moved to fsm_irq() which is called under mutex.
fsm_irq() returns VFIO_CCW_STATE_IDLE.
}
static void vfio_ccw_sch_event_todo(struct work_struct *work)
--
Pierre Morel
Linux/KVM/QEMU in Böblingen - Germany
