Re: [PATCH v3 05/25] bus: mhi: Make mhi_state_str[] array static inline and move to common.h

[Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>]

On Tue, Feb 15, 2022 at 02:02:21PM -0600, Alex Elder wrote:
> On 2/12/22 12:20 PM, Manivannan Sadhasivam wrote:
> > mhi_state_str[] array could be used by MHI endpoint stack also. So let's
> > make the array as "static inline function" and move it inside the
> > "common.h" header so that the endpoint stack could also make use of it.
> > 
> > Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
> 
> I like the use of a function to encapsulate this rather than
> using the array as before.
> 
> But I still don't like declaring this much static data in a static inline
> function in a header file.  Define it as a "real" function
> somewhere common and declare it here instead.
> 

The problem is we don't have a common c file to define this as a
function. Even if we add one, then it would be an overkill.

This pattern is more commonly used throughout the kernel source.

> One more minor comment below.
> 
> 					-Alex
> 
> > ---
> >   drivers/bus/mhi/common.h       | 29 +++++++++++++++++++++++++----
> >   drivers/bus/mhi/host/boot.c    |  2 +-
> >   drivers/bus/mhi/host/debugfs.c |  6 +++---
> >   drivers/bus/mhi/host/init.c    | 12 ------------
> >   drivers/bus/mhi/host/main.c    |  8 ++++----
> >   drivers/bus/mhi/host/pm.c      | 14 +++++++-------
> >   6 files changed, 40 insertions(+), 31 deletions(-)
> > 
> > diff --git a/drivers/bus/mhi/common.h b/drivers/bus/mhi/common.h
> > index 0d13a202d334..288e47168649 100644
> > --- a/drivers/bus/mhi/common.h
> > +++ b/drivers/bus/mhi/common.h
> > @@ -159,9 +159,30 @@ struct mhi_cmd_ctxt {
> >   	__le64 wp __packed __aligned(4);
> >   };
> > -extern const char * const mhi_state_str[MHI_STATE_MAX];
> > -#define TO_MHI_STATE_STR(state) ((state >= MHI_STATE_MAX || \
> > -				  !mhi_state_str[state]) ? \
> > -				"INVALID_STATE" : mhi_state_str[state])
> > +static inline const char * const mhi_state_str(enum mhi_state state)
> > +{
> > +	switch (state) {
> > +	case MHI_STATE_RESET:
> > +		return "RESET";
> > +	case MHI_STATE_READY:
> > +		return "READY";
> > +	case MHI_STATE_M0:
> > +		return "M0";
> > +	case MHI_STATE_M1:
> > +		return "M1";
> > +	case MHI_STATE_M2:
> > +		return"M2";
> 
> Add space after "return" here and in a few places below.
> 

Ack.

Thanks,
Mani

> > +	case MHI_STATE_M3:
> > +		return"M3";
> > +	case MHI_STATE_M3_FAST:
> > +		return"M3 FAST";
> > +	case MHI_STATE_BHI:
> > +		return"BHI";
> > +	case MHI_STATE_SYS_ERR:
> > +		return "SYS ERROR";
> > +	default:
> > +		return "Unknown state";
> > +	}
> > +};
> >   #endif /* _MHI_COMMON_H */
> > diff --git a/drivers/bus/mhi/host/boot.c b/drivers/bus/mhi/host/boot.c
> > index 74295d3cc662..93cb705614c6 100644
> > --- a/drivers/bus/mhi/host/boot.c
> > +++ b/drivers/bus/mhi/host/boot.c
> > @@ -68,7 +68,7 @@ static int __mhi_download_rddm_in_panic(struct mhi_controller *mhi_cntrl)
> >   	dev_dbg(dev, "Entered with pm_state:%s dev_state:%s ee:%s\n",
> >   		to_mhi_pm_state_str(mhi_cntrl->pm_state),
> > -		TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > +		mhi_state_str(mhi_cntrl->dev_state),
> >   		TO_MHI_EXEC_STR(mhi_cntrl->ee));
> >   	/*
> > diff --git a/drivers/bus/mhi/host/debugfs.c b/drivers/bus/mhi/host/debugfs.c
> > index d818586c229d..399d0db1f1eb 100644
> > --- a/drivers/bus/mhi/host/debugfs.c
> > +++ b/drivers/bus/mhi/host/debugfs.c
> > @@ -20,7 +20,7 @@ static int mhi_debugfs_states_show(struct seq_file *m, void *d)
> >   	seq_printf(m, "PM state: %s Device: %s MHI state: %s EE: %s wake: %s\n",
> >   		   to_mhi_pm_state_str(mhi_cntrl->pm_state),
> >   		   mhi_is_active(mhi_cntrl) ? "Active" : "Inactive",
> > -		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > +		   mhi_state_str(mhi_cntrl->dev_state),
> >   		   TO_MHI_EXEC_STR(mhi_cntrl->ee),
> >   		   mhi_cntrl->wake_set ? "true" : "false");
> > @@ -206,13 +206,13 @@ static int mhi_debugfs_regdump_show(struct seq_file *m, void *d)
> >   	seq_printf(m, "Host PM state: %s Device state: %s EE: %s\n",
> >   		   to_mhi_pm_state_str(mhi_cntrl->pm_state),
> > -		   TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > +		   mhi_state_str(mhi_cntrl->dev_state),
> >   		   TO_MHI_EXEC_STR(mhi_cntrl->ee));
> >   	state = mhi_get_mhi_state(mhi_cntrl);
> >   	ee = mhi_get_exec_env(mhi_cntrl);
> >   	seq_printf(m, "Device EE: %s state: %s\n", TO_MHI_EXEC_STR(ee),
> > -		   TO_MHI_STATE_STR(state));
> > +		   mhi_state_str(state));
> >   	for (i = 0; regs[i].name; i++) {
> >   		if (!regs[i].base)
> > diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> > index 4bd62f32695d..0e301f3f305e 100644
> > --- a/drivers/bus/mhi/host/init.c
> > +++ b/drivers/bus/mhi/host/init.c
> > @@ -44,18 +44,6 @@ const char * const dev_state_tran_str[DEV_ST_TRANSITION_MAX] = {
> >   	[DEV_ST_TRANSITION_DISABLE] = "DISABLE",
> >   };
> > -const char * const mhi_state_str[MHI_STATE_MAX] = {
> > -	[MHI_STATE_RESET] = "RESET",
> > -	[MHI_STATE_READY] = "READY",
> > -	[MHI_STATE_M0] = "M0",
> > -	[MHI_STATE_M1] = "M1",
> > -	[MHI_STATE_M2] = "M2",
> > -	[MHI_STATE_M3] = "M3",
> > -	[MHI_STATE_M3_FAST] = "M3 FAST",
> > -	[MHI_STATE_BHI] = "BHI",
> > -	[MHI_STATE_SYS_ERR] = "SYS ERROR",
> > -};
> > -
> >   const char * const mhi_ch_state_type_str[MHI_CH_STATE_TYPE_MAX] = {
> >   	[MHI_CH_STATE_TYPE_RESET] = "RESET",
> >   	[MHI_CH_STATE_TYPE_STOP] = "STOP",
> > diff --git a/drivers/bus/mhi/host/main.c b/drivers/bus/mhi/host/main.c
> > index 85f4f7c8d7c6..e436c2993d97 100644
> > --- a/drivers/bus/mhi/host/main.c
> > +++ b/drivers/bus/mhi/host/main.c
> > @@ -479,8 +479,8 @@ irqreturn_t mhi_intvec_threaded_handler(int irq_number, void *priv)
> >   	ee = mhi_get_exec_env(mhi_cntrl);
> >   	dev_dbg(dev, "local ee: %s state: %s device ee: %s state: %s\n",
> >   		TO_MHI_EXEC_STR(mhi_cntrl->ee),
> > -		TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > -		TO_MHI_EXEC_STR(ee), TO_MHI_STATE_STR(state));
> > +		mhi_state_str(mhi_cntrl->dev_state),
> > +		TO_MHI_EXEC_STR(ee), mhi_state_str(state));
> >   	if (state == MHI_STATE_SYS_ERR) {
> >   		dev_dbg(dev, "System error detected\n");
> > @@ -846,7 +846,7 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
> >   			new_state = MHI_TRE_GET_EV_STATE(local_rp);
> >   			dev_dbg(dev, "State change event to state: %s\n",
> > -				TO_MHI_STATE_STR(new_state));
> > +				mhi_state_str(new_state));
> >   			switch (new_state) {
> >   			case MHI_STATE_M0:
> > @@ -873,7 +873,7 @@ int mhi_process_ctrl_ev_ring(struct mhi_controller *mhi_cntrl,
> >   			}
> >   			default:
> >   				dev_err(dev, "Invalid state: %s\n",
> > -					TO_MHI_STATE_STR(new_state));
> > +					mhi_state_str(new_state));
> >   			}
> >   			break;
> > diff --git a/drivers/bus/mhi/host/pm.c b/drivers/bus/mhi/host/pm.c
> > index c35c5ddc7220..088ade0f3e0b 100644
> > --- a/drivers/bus/mhi/host/pm.c
> > +++ b/drivers/bus/mhi/host/pm.c
> > @@ -545,7 +545,7 @@ static void mhi_pm_disable_transition(struct mhi_controller *mhi_cntrl)
> >   	dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
> >   		to_mhi_pm_state_str(mhi_cntrl->pm_state),
> > -		TO_MHI_STATE_STR(mhi_cntrl->dev_state));
> > +		mhi_state_str(mhi_cntrl->dev_state));
> >   	mutex_unlock(&mhi_cntrl->pm_mutex);
> >   }
> > @@ -689,7 +689,7 @@ static void mhi_pm_sys_error_transition(struct mhi_controller *mhi_cntrl)
> >   exit_sys_error_transition:
> >   	dev_dbg(dev, "Exiting with PM state: %s, MHI state: %s\n",
> >   		to_mhi_pm_state_str(mhi_cntrl->pm_state),
> > -		TO_MHI_STATE_STR(mhi_cntrl->dev_state));
> > +		mhi_state_str(mhi_cntrl->dev_state));
> >   	mutex_unlock(&mhi_cntrl->pm_mutex);
> >   }
> > @@ -864,7 +864,7 @@ int mhi_pm_suspend(struct mhi_controller *mhi_cntrl)
> >   	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
> >   		dev_err(dev,
> >   			"Did not enter M3 state, MHI state: %s, PM state: %s\n",
> > -			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > +			mhi_state_str(mhi_cntrl->dev_state),
> >   			to_mhi_pm_state_str(mhi_cntrl->pm_state));
> >   		return -EIO;
> >   	}
> > @@ -890,7 +890,7 @@ static int __mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force)
> >   	dev_dbg(dev, "Entered with PM state: %s, MHI state: %s\n",
> >   		to_mhi_pm_state_str(mhi_cntrl->pm_state),
> > -		TO_MHI_STATE_STR(mhi_cntrl->dev_state));
> > +		mhi_state_str(mhi_cntrl->dev_state));
> >   	if (mhi_cntrl->pm_state == MHI_PM_DISABLE)
> >   		return 0;
> > @@ -900,7 +900,7 @@ static int __mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force)
> >   	if (mhi_get_mhi_state(mhi_cntrl) != MHI_STATE_M3) {
> >   		dev_warn(dev, "Resuming from non M3 state (%s)\n",
> > -			 TO_MHI_STATE_STR(mhi_get_mhi_state(mhi_cntrl)));
> > +			 mhi_state_str(mhi_get_mhi_state(mhi_cntrl)));
> >   		if (!force)
> >   			return -EINVAL;
> >   	}
> > @@ -937,7 +937,7 @@ static int __mhi_pm_resume(struct mhi_controller *mhi_cntrl, bool force)
> >   	if (!ret || MHI_PM_IN_ERROR_STATE(mhi_cntrl->pm_state)) {
> >   		dev_err(dev,
> >   			"Did not enter M0 state, MHI state: %s, PM state: %s\n",
> > -			TO_MHI_STATE_STR(mhi_cntrl->dev_state),
> > +			mhi_state_str(mhi_cntrl->dev_state),
> >   			to_mhi_pm_state_str(mhi_cntrl->pm_state));
> >   		return -EIO;
> >   	}
> > @@ -1088,7 +1088,7 @@ int mhi_async_power_up(struct mhi_controller *mhi_cntrl)
> >   	state = mhi_get_mhi_state(mhi_cntrl);
> >   	dev_dbg(dev, "Attempting power on with EE: %s, state: %s\n",
> > -		TO_MHI_EXEC_STR(current_ee), TO_MHI_STATE_STR(state));
> > +		TO_MHI_EXEC_STR(current_ee), mhi_state_str(state));
> >   	if (state == MHI_STATE_SYS_ERR) {
> >   		mhi_set_mhi_state(mhi_cntrl, MHI_STATE_RESET);
>