| Message ID | 1617070307-5775-1-git-send-email-bbhatt@codeaurora.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | Updates to MHI channel handling | expand |
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 >
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. 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(-)