Re: [PATCH v6 7/8] bus: mhi: Improve documentation on channel transfer setup APIs

[Manivannan Sadhasivam]

On Thu, Feb 04, 2021 at 12:28:05PM -0800, Bhaumik Bhatt wrote:
> The mhi_prepare_for_transfer() and mhi_unprepare_from_transfer()
> APIs could use better explanation. Add details on what MHI does
> when these APIs are used.
> 
> Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> Reviewed-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>

Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>

Thanks,
Mani

> ---
>  include/linux/mhi.h | 18 ++++++++++++++++--
>  1 file changed, 16 insertions(+), 2 deletions(-)
> 
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index d26acc8..56c4c52 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -712,13 +712,27 @@ int mhi_device_get_sync(struct mhi_device *mhi_dev);
>  void mhi_device_put(struct mhi_device *mhi_dev);
>  
>  /**
> - * mhi_prepare_for_transfer - Setup channel for data transfer
> + * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
> + *                            Allocate and initialize the channel context and
> + *                            also issue the START channel command to both
> + *                            channels. Channels can be started only if both
> + *                            host and device execution environments match and
> + *                            channels are in a DISABLED state.
>   * @mhi_dev: Device associated with the channels
>   */
>  int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
>  
>  /**
> - * mhi_unprepare_from_transfer - Unprepare the channels
> + * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
> + *                               Issue the RESET channel command and let the
> + *                               device clean-up the context so no incoming
> + *                               transfers are seen on the host. Free memory
> + *                               associated with the context on host. If device
> + *                               is unresponsive, only perform a host side
> + *                               clean-up. Channels can be reset only if both
> + *                               host and device execution environments match
> + *                               and channels are in an ENABLED, STOPPED or
> + *                               SUSPENDED state.
>   * @mhi_dev: Device associated with the channels
>   */
>  void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);
> -- 
> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
> a Linux Foundation Collaborative Project
>