[v1,0/4] Updates to MHI channel handling

Message

Bhaumik Bhatt Nov. 9, 2020, 10:44 p.m. UTC

MHI specification shows a state machine with support for STOP channel command
and the validity of certain state transitions. MHI host currently does not
provide any mechanism to stop a channel and restart it without resetting it.
There are also times when the device moves on to a different execution
environment while client drivers on the host are unaware of it and still
attempt to reset the channels facing unnecessary timeouts.

This series addresses the above areas to provide support for stopping an MHI
channel, resuming it back, and improving upon channel state machine handling in
general.

This set of patches was tested on arm64 architecture.

Bhaumik Bhatt (4):
  bus: mhi: core: Allow receiving a STOP channel command response
  bus: mhi: core: Improvements to the channel handling state machine
  bus: mhi: core: Add support to pause or resume channel data transfers
  bus: mhi: core: Check execution environment for channel before issuing
    reset

 drivers/bus/mhi/core/init.c     |  11 +-
 drivers/bus/mhi/core/internal.h |  12 +++
 drivers/bus/mhi/core/main.c     | 218 ++++++++++++++++++++++++++++------------
 include/linux/mhi.h             |  16 +++
 4 files changed, 192 insertions(+), 65 deletions(-)