diff mbox series

[v6,5/8] bus: mhi: core: Check channel execution environment before issuing reset

Message ID 1612470486-10440-6-git-send-email-bbhatt@codeaurora.org
State Superseded
Headers show
Series Updates to MHI channel handling | expand

Commit Message

Bhaumik Bhatt Feb. 4, 2021, 8:28 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>
---
 drivers/bus/mhi/core/main.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

Comments

Manivannan Sadhasivam Feb. 24, 2021, 10:07 a.m. UTC | #1
On Thu, Feb 04, 2021 at 12:28:03PM -0800, 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>


Thanks,
Mani

> ---

>  drivers/bus/mhi/core/main.c | 11 +++++++++++

>  1 file changed, 11 insertions(+)

> 

> diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c

> index 2f6fdb2..f511e3a 100644

> --- a/drivers/bus/mhi/core/main.c

> +++ b/drivers/bus/mhi/core/main.c

> @@ -1283,6 +1283,12 @@ 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);

> @@ -1290,6 +1296,11 @@ 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);

> -- 

> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,

> a Linux Foundation Collaborative Project

>
diff mbox series

Patch

diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
index 2f6fdb2..f511e3a 100644
--- a/drivers/bus/mhi/core/main.c
+++ b/drivers/bus/mhi/core/main.c
@@ -1283,6 +1283,12 @@  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);
@@ -1290,6 +1296,11 @@  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);