2021-01-08 20:58:15

by Bhaumik Bhatt

Subject: [PATCH v5 2/9] bus: mhi: core: Allow channel to be disabled from stopped state

If a channel was explicitly stopped but not reset, allow it to
move to a disabled state so that the channel context can be
cleaned up after a driver remove is issued. Since the channel
remained in stopped state, its context on the device is not
cleared. Allow this move if a client driver module is unloaded
or a device crash occurs.

Signed-off-by: Bhaumik Bhatt <[email protected]>
Reviewed-by: Hemant Kumar <[email protected]>
---
drivers/bus/mhi/core/init.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
index aa575d3..03c5786 100644
--- a/drivers/bus/mhi/core/init.c
+++ b/drivers/bus/mhi/core/init.c
@@ -1293,7 +1293,8 @@ static int mhi_driver_remove(struct device *dev)

mutex_lock(&mhi_chan->mutex);

- if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
+ if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
+ ch_state[dir] == MHI_CH_STATE_STOP) &&
!mhi_chan->offload_ch)
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

2021-01-21 11:38:23

by Manivannan Sadhasivam

Subject: Re: [PATCH v5 2/9] bus: mhi: core: Allow channel to be disabled from stopped state

On Fri, Jan 08, 2021 at 12:54:50PM -0800, Bhaumik Bhatt wrote:
> If a channel was explicitly stopped but not reset, allow it to
> move to a disabled state so that the channel context can be
> cleaned up after a driver remove is issued. Since the channel
> remained in stopped state, its context on the device is not
> cleared. Allow this move if a client driver module is unloaded
> or a device crash occurs.
>

The commit message needs to be improved. The stopped channel will by default
move to stopped state during mhi_driver_remove(). So this patch is not at all
doing anything other than clearing the context for stopped channels.

Please fix it!

> Signed-off-by: Bhaumik Bhatt <[email protected]>
> Reviewed-by: Hemant Kumar <[email protected]>

Reviewed-by: Manivannan Sadhasivam <[email protected]>

Thanks,
Mani

> ---
> drivers/bus/mhi/core/init.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> index aa575d3..03c5786 100644
> --- a/drivers/bus/mhi/core/init.c
> +++ b/drivers/bus/mhi/core/init.c
> @@ -1293,7 +1293,8 @@ static int mhi_driver_remove(struct device *dev)
>
> mutex_lock(&mhi_chan->mutex);
>
> - if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
> + if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
> + ch_state[dir] == MHI_CH_STATE_STOP) &&
> !mhi_chan->offload_ch)
> 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
>