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From: Bhaumik Bhatt <>
	Bhaumik Bhatt <>
Subject: [PATCH v4 6/8] bus: mhi: core: Check channel execution environment before issuing reset
Date: Thu,  3 Dec 2020 17:23:15 -0800	[thread overview]
Message-ID: <> (raw)
In-Reply-To: <>

A client can attempt to unprepare certain channels for transfer even
after the execution environment they are supposed to run in has changed.
In the event that happens, the device need not be notified of the reset
and the host can proceed with clean up for the channel context and
memory allocated for it on the host as the device will no longer be able
to respond to such a request.

Signed-off-by: Bhaumik Bhatt <>
Reviewed-by: Hemant Kumar <>
 drivers/bus/mhi/core/main.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 064f313..f4026af 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1320,11 +1320,24 @@ static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
 	/* no more processing events for this channel */
+	if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
+		dev_err(dev,
+			"Current EE: %s Required EE Mask: 0x%x for chan: %s\n",
+			TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask,
+			mhi_chan->name);
+		goto exit_unprepare_channel;
+	}
 	ret = mhi_update_channel_state(mhi_cntrl, mhi_chan,
 	if (ret)
 		dev_err(dev, "Failed to reset channel, still resetting\n");
+	write_lock_irq(&mhi_chan->lock);
+	mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
+	write_unlock_irq(&mhi_chan->lock);
 	if (!mhi_chan->offload_ch) {
 		mhi_reset_chan(mhi_cntrl, mhi_chan);
 		mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
a Linux Foundation Collaborative Project

  parent reply	other threads:[~2020-12-04  1:24 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-12-04  1:23 [PATCH v4 0/8] Updates to MHI channel handling Bhaumik Bhatt
2020-12-04  1:23 ` [PATCH v4 1/8] bus: mhi: core: Allow sending the STOP channel command Bhaumik Bhatt
2020-12-04  3:44   ` Hemant Kumar
2020-12-04  1:23 ` [PATCH v4 2/8] bus: mhi: core: Allow channel to be disabled from stopped state Bhaumik Bhatt
2020-12-04  1:23 ` [PATCH v4 3/8] bus: mhi: core: Improvements to the channel handling state machine Bhaumik Bhatt
2020-12-04  1:23 ` [PATCH v4 4/8] bus: mhi: core: Clear configuration from channel context during reset Bhaumik Bhatt
2020-12-04  3:49   ` Hemant Kumar
2020-12-04  1:23 ` [PATCH v4 5/8] bus: mhi: core: Add support to stop or start channel data transfers Bhaumik Bhatt
2020-12-04  3:50   ` Hemant Kumar
2020-12-04  1:23 ` Bhaumik Bhatt [this message]
2020-12-04  1:23 ` [PATCH v4 7/8] bus: mhi: core: Remove __ prefix for MHI channel unprepare function Bhaumik Bhatt
2020-12-04  1:23 ` [PATCH v4 8/8] bus: mhi: Improve documentation on channel transfer setup APIs Bhaumik Bhatt

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