From 6731fefd95671575ceaba8e1c60881d529537352 Mon Sep 17 00:00:00 2001 From: Bhaumik Bhatt Date: Thu, 1 Apr 2021 14:16:18 -0700 Subject: [PATCH] bus: mhi: Improve documentation on channel transfer setup APIs 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 Reviewed-by: Hemant Kumar Reviewed-by: Manivannan Sadhasivam Link: https://lore.kernel.org/r/1617311778-1254-10-git-send-email-bbhatt@codeaurora.org Signed-off-by: Manivannan Sadhasivam --- 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 c9b36a34cc7f..d095fba37d1e 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); -- GitLab