Re: [PATCH v2 1/6] bus: mhi: core: Allow receiving a STOP channel command response

[Bhaumik Bhatt]

Hi Mani,

On 2020-11-15 23:13, Manivannan Sadhasivam wrote:
> On Wed, Nov 11, 2020 at 11:21:08AM -0800, Bhaumik Bhatt wrote:
> > Add support to receive the response to a STOP channel command to the
> > MHI bus. If a client would like to STOP a channel instead of issuing
> > a RESET to it, this would provide support for it.
> >
> > Signed-off-by: Bhaumik Bhatt <bbhatt@xxxxxxxxxxxxxx>
> > ---
> >  drivers/bus/mhi/core/init.c | 5 +++--
> >  drivers/bus/mhi/core/main.c | 5 +++++
> >  2 files changed, 8 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/bus/mhi/core/init.c b/drivers/bus/mhi/core/init.c
> > index 8cefa35..4d34d62 100644
> > --- a/drivers/bus/mhi/core/init.c
> > +++ b/drivers/bus/mhi/core/init.c
> > @@ -1267,8 +1267,9 @@ static int mhi_driver_remove(struct device *dev)
> >
> >  		mutex_lock(&mhi_chan->mutex);
> >
> > -		if (ch_state[dir] == MHI_CH_STATE_ENABLED &&
> > -		    !mhi_chan->offload_ch)
> > +		if ((ch_state[dir] == MHI_CH_STATE_ENABLED ||
> > +		     ch_state[dir] == MHI_CH_STATE_STOP) &&
>
> This enum is not defined in this patch so it'll break. Please add a 
> separate
> patch which introduces the new state enums alone and then have patches 
> 1/2
> as a followup.
It is actually already defined and present in internal.h as enum 
mhi_ch_state.

The old set of enums has MHI_CH_STATE_STOP from enum mhi_ch_state and 
the new
enum I introduced is MHI_CH_STATE_TYPE_STOP from enum enum 
mhi_ch_state_type.

If it seems confusing, suggestions to renaming them are welcome.

> Also this change is not belonging to this commit I believe.
I included this change here because, a channel can be in "stopped" state 
and
a user module could be unloaded or a crash could force a driver remove 
leading
us to come this check.

If you think I should move it as a separate patch, let me know.
> Thanks,
> Mani
>
> > +		     !mhi_chan->offload_ch)
> >  			mhi_deinit_chan_ctxt(mhi_cntrl, mhi_chan);
> >
> >  		mhi_chan->ch_state = MHI_CH_STATE_DISABLED;
> > diff --git a/drivers/bus/mhi/core/main.c b/drivers/bus/mhi/core/main.c
> > index f953e2a..ad881a1 100644
> > --- a/drivers/bus/mhi/core/main.c
> > +++ b/drivers/bus/mhi/core/main.c
> > @@ -1194,6 +1194,11 @@ int mhi_send_cmd(struct mhi_controller 
> > *mhi_cntrl,
> >  		cmd_tre->dword[0] = MHI_TRE_CMD_RESET_DWORD0;
> >  		cmd_tre->dword[1] = MHI_TRE_CMD_RESET_DWORD1(chan);
> >  		break;
> > +	case MHI_CMD_STOP_CHAN:
> > +		cmd_tre->ptr = MHI_TRE_CMD_STOP_PTR;
> > +		cmd_tre->dword[0] = MHI_TRE_CMD_STOP_DWORD0;
> > +		cmd_tre->dword[1] = MHI_TRE_CMD_STOP_DWORD1(chan);
> > +		break;
> >  	case MHI_CMD_START_CHAN:
> >  		cmd_tre->ptr = MHI_TRE_CMD_START_PTR;
> >  		cmd_tre->dword[0] = MHI_TRE_CMD_START_DWORD0;
> > --
> > The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
> > Forum,
> > a Linux Foundation Collaborative Project

Thanks,
Bhaumik
--
The Qualcomm Innovation Center, Inc. is a member of the Code Aurora 
Forum,
a Linux Foundation Collaborative Project