On Mon, Mar 29, 2021 at 07:11:40PM -0700, Bhaumik Bhatt wrote: > 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, improved documentation and improving upon channel > state machine handling in general. > > This set of patches was tested on arm64 and x86_64 architecture. > Please rebase this series on top of mhi-next as some of the patches doesn't apply cleanly. Thanks, Mani > v7: > -Tested on x86_64 architecture > -Drop the patch "Do not clear channel context more than once" as issue is fixed > differently using "bus: mhi: core: Fix double dma free()" > -Update the commit text to better reflect changes on state machine improvements > > v6: > -Dropped the patch which introduced start/stop transfer APIs for lack of users > -Updated error handling and debug prints on channel handling improvements patch > -Improved commit text to better explain certain patches based on review comments > -Removed references to new APIs from the documentation improvement patch > > v5: > -Added reviewed-by tags from Hemant I missed earlier > -Added patch to prevent kernel warnings on clearing channel context twice > > v4: > -Updated commit text/descriptions and addressed checkpatch checks > -Added context validity check before starting/stopping channels from new API > -Added patch to clear channel context configuration after reset/unprepare > > v3: > -Updated documentation for channel transfer APIs to highlight differences > -Create separate patch for "allowing channel to be disabled from stopped state" > > v2: > -Renamed the newly introduced APIs to mhi_start_transfer() / mhi_stop_transfer() > -Added improved documentation to avoid confusion with the new APIs > -Removed the __ prefix from mhi_unprepare_channel() API for consistency. > > Bhaumik Bhatt (7): > bus: mhi: core: Allow sending the STOP channel command > bus: mhi: core: Clear context for stopped channels from remove() > bus: mhi: core: Improvements to the channel handling state machine > bus: mhi: core: Clear configuration from channel context during reset > bus: mhi: core: Check channel execution environment before issuing > reset > bus: mhi: core: Remove __ prefix for MHI channel unprepare function > bus: mhi: Improve documentation on channel transfer setup APIs > > drivers/bus/mhi/core/init.c | 22 ++++- > drivers/bus/mhi/core/internal.h | 12 +++ > drivers/bus/mhi/core/main.c | 192 ++++++++++++++++++++++++---------------- > include/linux/mhi.h | 18 +++- > 4 files changed, 163 insertions(+), 81 deletions(-) > > -- > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum, > a Linux Foundation Collaborative Project >
