Re: [PATCH v6 7/8] bus: mhi: Improve documentation on channel transfer setup APIs
From: Manivannan Sadhasivam
Date: Wed Feb 24 2021 - 05:09:55 EST
On Thu, Feb 04, 2021 at 12:28:05PM -0800, Bhaumik Bhatt wrote:
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The mhi_prepare_for_transfer() and mhi_unprepare_from_transfer()
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APIs could use better explanation. Add details on what MHI does
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when these APIs are used.
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Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
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Reviewed-by: Hemant Kumar <hemantk@xxxxxxxxxxxxxx>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
Thanks,
Mani
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---
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include/linux/mhi.h | 18 ++++++++++++++++--
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1 file changed, 16 insertions(+), 2 deletions(-)
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diff --git a/include/linux/mhi.h b/include/linux/mhi.h
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index d26acc8..56c4c52 100644
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--- a/include/linux/mhi.h
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+++ b/include/linux/mhi.h
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@@ -712,13 +712,27 @@ int mhi_device_get_sync(struct mhi_device *mhi_dev);
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void mhi_device_put(struct mhi_device *mhi_dev);
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/**
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- * mhi_prepare_for_transfer - Setup channel for data transfer
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+ * mhi_prepare_for_transfer - Setup UL and DL channels for data transfer.
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+ * Allocate and initialize the channel context and
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+ * also issue the START channel command to both
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+ * channels. Channels can be started only if both
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+ * host and device execution environments match and
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+ * channels are in a DISABLED state.
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* @mhi_dev: Device associated with the channels
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*/
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int mhi_prepare_for_transfer(struct mhi_device *mhi_dev);
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/**
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- * mhi_unprepare_from_transfer - Unprepare the channels
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+ * mhi_unprepare_from_transfer - Reset UL and DL channels for data transfer.
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+ * Issue the RESET channel command and let the
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+ * device clean-up the context so no incoming
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+ * transfers are seen on the host. Free memory
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+ * associated with the context on host. If device
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+ * is unresponsive, only perform a host side
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+ * clean-up. Channels can be reset only if both
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+ * host and device execution environments match
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+ * and channels are in an ENABLED, STOPPED or
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+ * SUSPENDED state.
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* @mhi_dev: Device associated with the channels
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*/
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void mhi_unprepare_from_transfer(struct mhi_device *mhi_dev);
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--
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