[v8,7/9] bus: mhi: core: Check channel execution environment before issuing reset
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Message ID 1617311778-1254-8-git-send-email-bbhatt@codeaurora.org
State Accepted
Commit 8e06e9fb990975a55b64c6e4c5b6b183962f849a
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Series
  • [v8,1/9] bus: mhi: core: Allow sending the STOP channel command
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Commit Message

Bhaumik Bhatt April 1, 2021, 9:16 p.m. UTC
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 <bbhatt@codeaurora.org>
Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
---
 drivers/bus/mhi/core/main.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Jeffrey Hugo May 4, 2021, 5:49 p.m. UTC | #1
On 4/1/2021 3:16 PM, Bhaumik Bhatt wrote:
> 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 <bbhatt@codeaurora.org>
> Reviewed-by: Hemant Kumar <hemantk@codeaurora.org>
> Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> ---

Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>

Patch
diff mbox series

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 989a2a8..04480fd 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1329,6 +1329,12 @@  static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
 
 	mutex_lock(&mhi_chan->mutex);
 
+	if (!(BIT(mhi_cntrl->ee) & mhi_chan->ee_mask)) {
+		dev_dbg(dev, "Current EE: %s Required EE Mask: 0x%x\n",
+			TO_MHI_EXEC_STR(mhi_cntrl->ee), mhi_chan->ee_mask);
+		goto exit_unprepare_channel;
+	}
+
 	/* no more processing events for this channel */
 	ret = mhi_update_channel_state(mhi_cntrl, mhi_chan,
 				       MHI_CH_STATE_TYPE_RESET);
@@ -1336,6 +1342,11 @@  static void __mhi_unprepare_channel(struct mhi_controller *mhi_cntrl,
 		dev_err(dev, "%d: Failed to reset channel, still resetting\n",
 			mhi_chan->chan);
 
+exit_unprepare_channel:
+	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);