tree a53eb05b225c532e1e0b6da9b2db6c5e15cafafb
parent 206c5f60a3d902bc4b56dab2de3e88de5eb06108
author Oded Gabbay <oded.gabbay@amd.com> 1415614899 +0200
committer Joerg Roedel <jroedel@suse.de> 1415800713 +0100

iommu/amd: Fix accounting of device_state

This patch fixes a bug in the accounting of the
device_state.  In the current code, the device_state was put
(decremented) too many times, which sometimes lead to the
driver getting stuck permanently in put_device_state_wait().
That happen because the device_state->count would go below
zero, which is never supposed to happen.

The root cause is that the device_state was decremented in
put_pasid_state() and put_pasid_state_wait() but also in all
the functions that call those functions. Therefore, the
device_state was decremented twice in each of these code
paths.

The fix is to decouple the device_state accounting from the
pasid_state accounting - remove the call to
put_device_state() from the put_pasid_state() and the
put_pasid_state_wait())

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>