Re: [PATCH v8 28/38] media: ccs: Compute scaling configuration from sub-device state

[Sakari Ailus <sakari.ailus@linux.intel.com>]

Hi Laurent,

On Thu, Mar 21, 2024 at 07:50:04PM +0200, Laurent Pinchart wrote:
> Hi Sakari,
> 
> Thank you for the patch.
> 
> On Wed, Mar 13, 2024 at 09:25:06AM +0200, Sakari Ailus wrote:
> > Compute scaling configuration from sub-device state instead of storing it
> > to the driver's device context struct.
> > 
> > Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
> > ---
> >  drivers/media/i2c/ccs/ccs-core.c | 60 ++++++++++++++++++++++----------
> >  drivers/media/i2c/ccs/ccs.h      |  3 --
> >  2 files changed, 41 insertions(+), 22 deletions(-)
> > 
> > diff --git a/drivers/media/i2c/ccs/ccs-core.c b/drivers/media/i2c/ccs/ccs-core.c
> > index 3b80c54453cc..a147dbb9f362 100644
> > --- a/drivers/media/i2c/ccs/ccs-core.c
> > +++ b/drivers/media/i2c/ccs/ccs-core.c
> > @@ -547,19 +547,52 @@ ccs_get_binning(struct ccs_sensor *sensor, u8 *binning_mode, u8 *binh, u8 *binv)
> >  		*binv = binner_sink_crop->height / binner_sink_comp->height;
> >  }
> >  
> > +static void ccs_get_scaling(struct ccs_sensor *sensor,
> > +			    u8 *scaling_mode, u8 *scale_m)
> > +{
> > +	struct v4l2_subdev_state *scaler_state =
> > +		v4l2_subdev_get_locked_active_state(&sensor->scaler->sd);
> 
> Have you double-checked that the scaler state is locked in all code
> paths that can lead to this ? The function is called at probe time, with
> a manual lock of sensor->mutex. That makes me a bit uncomfortable, I
> wonder if it wouldn't be better to pass the locked scaler state to the
> function explicitly, to let the callers guarantee the locking
> requirements.

Given that there's a single mutex and v4l2_subdev_get_locked_active_state()
also uses lockdep_assert_held(), I'm not really concerned.

> 
> > +	struct v4l2_rect *scaler_sink_crop =
> 
> const
> 
> I would also drop the scaler_ prefix here and for the next variable.

Works for me.

> 
> > +		v4l2_subdev_state_get_crop(scaler_state, CCS_PAD_SINK,
> > +					   CCS_STREAM_PIXEL);
> > +	struct v4l2_rect *scaler_sink_comp =
> > +		v4l2_subdev_state_get_compose(scaler_state, CCS_PAD_SINK,
> > +					      CCS_STREAM_PIXEL);
> > +
> > +	if (scale_m)
> > +		*scale_m = scaler_sink_crop->width *
> > +			CCS_LIM(sensor, SCALER_N_MIN) /
> > +			scaler_sink_comp->width;
> > +
> > +	if (scaling_mode) {
> > +		if (scaler_sink_crop->width == scaler_sink_comp->width)
> > +			*scaling_mode = CCS_SCALING_MODE_NO_SCALING;
> > +		else if (scaler_sink_crop->height == scaler_sink_comp->height)
> > +			*scaling_mode = CCS_SCALING_MODE_HORIZONTAL;
> > +		else
> > +			*scaling_mode = SMIAPP_SCALING_MODE_BOTH;
> > +	}
> > +}
> > +
> >  static int ccs_pll_update(struct ccs_sensor *sensor)
> >  {
> >  	struct ccs_pll *pll = &sensor->pll;
> >  	u8 binh, binv;
> > +	u8 scale_m;
> >  	int rval;
> >  
> >  	ccs_get_binning(sensor, NULL, &binh, &binv);
> >  
> > +	if (sensor->scaler)
> > +		ccs_get_scaling(sensor, NULL, &scale_m);
> > +	else
> > +		scale_m = CCS_LIM(sensor, SCALER_N_MIN);
> > +
> >  	pll->binning_horizontal = binh;
> >  	pll->binning_vertical = binv;
> >  	pll->link_freq =
> >  		sensor->link_freq->qmenu_int[sensor->link_freq->val];
> > -	pll->scale_m = sensor->scale_m;
> > +	pll->scale_m = scale_m;
> >  	pll->bits_per_pixel = sensor->csi_format->compressed;
> >  
> >  	rval = ccs_pll_try(sensor, pll);
> > @@ -1202,7 +1235,7 @@ static int ccs_get_mbus_formats(struct ccs_sensor *sensor)
> >  	/* Figure out which BPP values can be used with which formats. */
> >  	pll->binning_horizontal = 1;
> >  	pll->binning_vertical = 1;
> > -	pll->scale_m = sensor->scale_m;
> > +	pll->scale_m = CCS_LIM(sensor, SCALER_N_MIN);
> >  
> >  	for (i = 0; i < ARRAY_SIZE(ccs_csi_data_formats); i++) {
> >  		sensor->compressed_min_bpp =
> > @@ -1950,11 +1983,15 @@ static int ccs_enable_streams(struct v4l2_subdev *subdev,
> >  	/* Scaling */
> >  	if (CCS_LIM(sensor, SCALING_CAPABILITY)
> >  	    != CCS_SCALING_CAPABILITY_NONE) {
> > -		rval = ccs_write(sensor, SCALING_MODE, sensor->scaling_mode);
> > +		u8 scaling_mode, scale_m;
> > +
> > +		ccs_get_scaling(sensor, &scaling_mode, &scale_m);
> > +
> > +		rval = ccs_write(sensor, SCALING_MODE, scaling_mode);
> >  		if (rval < 0)
> >  			goto err_pm_put;
> >  
> > -		rval = ccs_write(sensor, SCALE_M, sensor->scale_m);
> > +		rval = ccs_write(sensor, SCALE_M, scale_m);
> >  		if (rval < 0)
> >  			goto err_pm_put;
> >  	}
> > @@ -2270,7 +2307,6 @@ static void ccs_propagate(struct v4l2_subdev *subdev,
> >  			  struct v4l2_subdev_state *sd_state, int which,
> >  			  int target)
> >  {
> > -	struct ccs_sensor *sensor = to_ccs_sensor(subdev);
> >  	struct ccs_subdev *ssd = to_ccs_subdev(subdev);
> >  	struct v4l2_rect *comp, *crop;
> >  	struct v4l2_mbus_framefmt *fmt;
> > @@ -2283,13 +2319,6 @@ static void ccs_propagate(struct v4l2_subdev *subdev,
> >  						  CCS_STREAM_PIXEL);
> >  		comp->width = crop->width;
> >  		comp->height = crop->height;
> > -		if (which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> > -			if (ssd == sensor->scaler) {
> > -				sensor->scale_m = CCS_LIM(sensor, SCALER_N_MIN);
> > -				sensor->scaling_mode =
> > -					CCS_SCALING_MODE_NO_SCALING;
> > -			}
> > -		}
> >  		fallthrough;
> >  	case V4L2_SEL_TGT_COMPOSE:
> >  		crop = v4l2_subdev_state_get_crop(sd_state, CCS_PAD_SRC,
> > @@ -2674,11 +2703,6 @@ static void ccs_set_compose_scaler(struct v4l2_subdev *subdev,
> >  			& ~1;
> >  	else
> >  		sel->r.height = sink_crop->height;
> > -
> > -	if (sel->which == V4L2_SUBDEV_FORMAT_ACTIVE) {
> > -		sensor->scale_m = scale_m;
> > -		sensor->scaling_mode = mode;
> > -	}
> >  }
> >  /* We're only called on source pads. This function sets scaling. */
> >  static int ccs_set_compose(struct v4l2_subdev *subdev,
> > @@ -3785,8 +3809,6 @@ static int ccs_probe(struct i2c_client *client)
> >  	sensor->pixel_array = &sensor->ssds[sensor->ssds_used];
> >  	sensor->ssds_used++;
> >  
> > -	sensor->scale_m = CCS_LIM(sensor, SCALER_N_MIN);
> > -
> >  	/* prepare PLL configuration input values */
> >  	sensor->pll.bus_type = CCS_PLL_BUS_TYPE_CSI2_DPHY;
> >  	sensor->pll.csi2.lanes = sensor->hwcfg.lanes;
> > diff --git a/drivers/media/i2c/ccs/ccs.h b/drivers/media/i2c/ccs/ccs.h
> > index e6fc00a9fa11..d33014f2710b 100644
> > --- a/drivers/media/i2c/ccs/ccs.h
> > +++ b/drivers/media/i2c/ccs/ccs.h
> > @@ -237,9 +237,6 @@ struct ccs_sensor {
> >  	u32 embedded_mbus_code;
> >  	u8 emb_data_ctrl;
> >  
> > -	u8 scale_m;
> > -	u8 scaling_mode;
> > -
> >  	u8 frame_skip;
> >  	u16 embedded_start; /* embedded data start line */
> >  	u16 embedded_end;
> 

-- 
Regards,

Sakari Ailus