msm: wb: Ensure iommu reference is available in wb terminate

In static screen case on command mode, when wifi display is
disconnected, buffers don't get free as there is a probability
that iommu is not attached. Ensure that iommu is attached when
wifi display terminate is called.

Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>

Change-Id: I9f5bb9db3024117da36f0c90af3c9f27ff27873f
msm: mdss: Add error handling support for DCS command APIs

Currently there is no error handling done for DSI DCS command
APIs like mdss_dsi_cmdlist_put. So for ESD thread use cases,
the caller functions of these DCS command APIs do not have error
propagated if the panel read/write commands fail. Hence add support
for error handling for these functions.

Change-Id: I0e558fd32fbfd8ae247b60c92fa2756159c3d3c6
Signed-off-by: Padmanabhan Komanduru <pkomandu@codeaurora.org>
msm: mdss: synchronize recovery handler access

The recovery handler is used in the dsi event thread, and
the recovery handler variable was configured from a different
thread.  Earlier, there is no synchronization between the two
threads accessing the recovery handler, causing kernel panics.

Change-Id: Iee990276fdabd65e2e1f2e3c21ad574fc0d8a7bc
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>