Re: [PATCH v7 0/7] Updates to MHI channel handling

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

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(-)
> 
> -- 
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