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Date:   Fri, 19 Aug 2022 09:40:03 +0200
From:   Jacopo Mondi <jacopo@jmondi.org>
To:     Marco Felsch <m.felsch@pengutronix.de>
Cc:     mchehab@kernel.org, sakari.ailus@linux.intel.com,
        laurent.pinchart+renesas@ideasonboard.com,
        jacopo+renesas@jmondi.org, akinobu.mita@gmail.com,
        linux-media@vger.kernel.org, linux-kernel@vger.kernel.org,
        kernel@pengutronix.de
Subject: Re: [PATCH 2/4] media: mt9m111: fix subdev API usage
Message-ID: <20220819074003.l3f5revgmmfmzya3@uno.localdomain>
References: <20220818144712.997477-1-m.felsch@pengutronix.de>
 <20220818144712.997477-2-m.felsch@pengutronix.de>
 <20220819071619.brhhbypmnt5pr2f7@uno.localdomain>
 <20220819072804.j6qj2r2mqrzcdmsg@pengutronix.de>
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In-Reply-To: <20220819072804.j6qj2r2mqrzcdmsg@pengutronix.de>
Precedence: bulk

Hi Marco

On Fri, Aug 19, 2022 at 09:28:04AM +0200, Marco Felsch wrote:
> Hi Jacopo,
>
> On 22-08-19, Jacopo Mondi wrote:
> > Hi Marco
> >
> > On Thu, Aug 18, 2022 at 04:47:10PM +0200, Marco Felsch wrote:
> > > In case of I2C transfer failures the driver return failure codes which
> > > are not allowed according the API documentation. Fix that by ignore the
> > > register access failure codes.
> >
> > I might have missed the reason why subdev ops are not allowed to
> > fail..
>
> Please see the links below:
>
> https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/vidioc-subdev-g-fmt.html?highlight=subdev_s_fmt#return-value
> https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/vidioc-subdev-g-selection.html#return-value
> https://www.kernel.org/doc/html/latest/userspace-api/media/v4l/vidioc-g-ext-ctrls.html#return-value
>
> There is e.g. no ENXIO error code allowed.

Ah ok, my understanding is that you were removing all return values.

I don't think un-checked HW access is a good idea though ?

You should remove HW access from the subdev ops and move the driver to
setup formats/controls at s_stream() time, like you're doing in the
next patches.

>
> > Also you're here changing both subdev ops handler and function that handle
> > controls if I'm not mistaken.
>
> Yes I did that for the controls because the errors are incorrect there
> as well. You're right, I forgot to mention this in the commit message.
>
> Regards,
>   Marco
>
> > > Signed-off-by: Marco Felsch <m.felsch@pengutronix.de>
> > > ---
> > >  drivers/media/i2c/mt9m111.c | 116 ++++++++++++++++++++----------------
> > >  1 file changed, 66 insertions(+), 50 deletions(-)
> > >
> > > diff --git a/drivers/media/i2c/mt9m111.c b/drivers/media/i2c/mt9m111.c
> > > index cdaf283e1309..53c4dac4e4bd 100644
> > > --- a/drivers/media/i2c/mt9m111.c
> > > +++ b/drivers/media/i2c/mt9m111.c
> > > @@ -455,7 +455,7 @@ static int mt9m111_set_selection(struct v4l2_subdev *sd,
> > >  	struct mt9m111 *mt9m111 = to_mt9m111(client);
> > >  	struct v4l2_rect rect = sel->r;
> > >  	int width, height;
> > > -	int ret, align = 0;
> > > +	int align = 0;
> > >
> > >  	if (sel->which != V4L2_SUBDEV_FORMAT_ACTIVE ||
> > >  	    sel->target != V4L2_SEL_TGT_CROP)
> > > @@ -481,14 +481,13 @@ static int mt9m111_set_selection(struct v4l2_subdev *sd,
> > >  	width = min(mt9m111->width, rect.width);
> > >  	height = min(mt9m111->height, rect.height);
> > >
> > > -	ret = mt9m111_setup_geometry(mt9m111, &rect, width, height, mt9m111->fmt->code);
> > > -	if (!ret) {
> > > -		mt9m111->rect = rect;
> > > -		mt9m111->width = width;
> > > -		mt9m111->height = height;
> > > -	}
> > >
> > > -	return ret;
> > > +	mt9m111_setup_geometry(mt9m111, &rect, width, height, mt9m111->fmt->code);
> > > +	mt9m111->rect = rect;
> > > +	mt9m111->width = width;
> > > +	mt9m111->height = height;
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_get_selection(struct v4l2_subdev *sd,
> > > @@ -558,7 +557,6 @@ static int mt9m111_set_pixfmt(struct mt9m111 *mt9m111,
> > >  		MT9M111_OUTFMT_RGB444x | MT9M111_OUTFMT_RGBx444 |
> > >  		MT9M111_OUTFMT_SWAP_YCbCr_C_Y_RGB_EVEN |
> > >  		MT9M111_OUTFMT_SWAP_YCbCr_Cb_Cr_RGB_R_B;
> > > -	int ret;
> > >
> > >  	switch (code) {
> > >  	case MEDIA_BUS_FMT_SBGGR8_1X8:
> > > @@ -613,13 +611,13 @@ static int mt9m111_set_pixfmt(struct mt9m111 *mt9m111,
> > >  	if (mt9m111->pclk_sample == 0)
> > >  		mask_outfmt2 |= MT9M111_OUTFMT_INV_PIX_CLOCK;
> > >
> > > -	ret = mt9m111_reg_mask(client, context_a.output_fmt_ctrl2,
> > > -			       data_outfmt2, mask_outfmt2);
> > > -	if (!ret)
> > > -		ret = mt9m111_reg_mask(client, context_b.output_fmt_ctrl2,
> > > -				       data_outfmt2, mask_outfmt2);
> > >
> > > -	return ret;
> > > +	mt9m111_reg_mask(client, context_a.output_fmt_ctrl2,
> > > +			 data_outfmt2, mask_outfmt2);
> > > +	mt9m111_reg_mask(client, context_b.output_fmt_ctrl2,
> > > +			 data_outfmt2, mask_outfmt2);
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_set_fmt(struct v4l2_subdev *sd,
> > > @@ -632,7 +630,6 @@ static int mt9m111_set_fmt(struct v4l2_subdev *sd,
> > >  	const struct mt9m111_datafmt *fmt;
> > >  	struct v4l2_rect *rect = &mt9m111->rect;
> > >  	bool bayer;
> > > -	int ret;
> > >
> > >  	if (mt9m111->is_streaming)
> > >  		return -EBUSY;
> > > @@ -681,16 +678,14 @@ static int mt9m111_set_fmt(struct v4l2_subdev *sd,
> > >  		return 0;
> > >  	}
> > >
> > > -	ret = mt9m111_setup_geometry(mt9m111, rect, mf->width, mf->height, mf->code);
> > > -	if (!ret)
> > > -		ret = mt9m111_set_pixfmt(mt9m111, mf->code);
> > > -	if (!ret) {
> > > -		mt9m111->width	= mf->width;
> > > -		mt9m111->height	= mf->height;
> > > -		mt9m111->fmt	= fmt;
> > > -	}
> > >
> > > -	return ret;
> > > +	mt9m111_setup_geometry(mt9m111, rect, mf->width, mf->height, mf->code);
> > > +	mt9m111_set_pixfmt(mt9m111, mf->code);
> > > +	mt9m111->width	= mf->width;
> > > +	mt9m111->height	= mf->height;
> > > +	mt9m111->fmt	= fmt;
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static const struct mt9m111_mode_info *
> > > @@ -786,14 +781,13 @@ static int mt9m111_s_register(struct v4l2_subdev *sd,
> > >  static int mt9m111_set_flip(struct mt9m111 *mt9m111, int flip, int mask)
> > >  {
> > >  	struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> > > -	int ret;
> > >
> > >  	if (flip)
> > > -		ret = mt9m111_reg_set(client, mt9m111->ctx->read_mode, mask);
> > > +		mt9m111_reg_set(client, mt9m111->ctx->read_mode, mask);
> > >  	else
> > > -		ret = mt9m111_reg_clear(client, mt9m111->ctx->read_mode, mask);
> > > +		mt9m111_reg_clear(client, mt9m111->ctx->read_mode, mask);
> > >
> > > -	return ret;
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_get_global_gain(struct mt9m111 *mt9m111)
> > > @@ -823,7 +817,9 @@ static int mt9m111_set_global_gain(struct mt9m111 *mt9m111, int gain)
> > >  	else
> > >  		val = gain;
> > >
> > > -	return reg_write(GLOBAL_GAIN, val);
> > > +	reg_write(GLOBAL_GAIN, val);
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_set_autoexposure(struct mt9m111 *mt9m111, int val)
> > > @@ -831,8 +827,11 @@ static int mt9m111_set_autoexposure(struct mt9m111 *mt9m111, int val)
> > >  	struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> > >
> > >  	if (val == V4L2_EXPOSURE_AUTO)
> > > -		return reg_set(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
> > > -	return reg_clear(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
> > > +		reg_set(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
> > > +	else
> > > +		reg_clear(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOEXPO_EN);
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_set_autowhitebalance(struct mt9m111 *mt9m111, int on)
> > > @@ -840,8 +839,11 @@ static int mt9m111_set_autowhitebalance(struct mt9m111 *mt9m111, int on)
> > >  	struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> > >
> > >  	if (on)
> > > -		return reg_set(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOWHITEBAL_EN);
> > > -	return reg_clear(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOWHITEBAL_EN);
> > > +		reg_set(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOWHITEBAL_EN);
> > > +	else
> > > +		reg_clear(OPER_MODE_CTRL, MT9M111_OPMODE_AUTOWHITEBAL_EN);
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static const char * const mt9m111_test_pattern_menu[] = {
> > > @@ -859,8 +861,9 @@ static int mt9m111_set_test_pattern(struct mt9m111 *mt9m111, int val)
> > >  {
> > >  	struct i2c_client *client = v4l2_get_subdevdata(&mt9m111->subdev);
> > >
> > > -	return mt9m111_reg_mask(client, MT9M111_TPG_CTRL, val,
> > > -				MT9M111_TPG_SEL_MASK);
> > > +	mt9m111_reg_mask(client, MT9M111_TPG_CTRL, val, MT9M111_TPG_SEL_MASK);
> > > +
> > > +	return 0;
> > >  }
> > >
> > >  static int mt9m111_set_colorfx(struct mt9m111 *mt9m111, int val)
> > > @@ -877,9 +880,10 @@ static int mt9m111_set_colorfx(struct mt9m111 *mt9m111, int val)
> > >
> > >  	for (i = 0; i < ARRAY_SIZE(colorfx); i++) {
> > >  		if (colorfx[i].id == val) {
> > > -			return mt9m111_reg_mask(client, MT9M111_EFFECTS_MODE,
> > > -						colorfx[i].value,
> > > -						MT9M111_EFFECTS_MODE_MASK);
> > > +			mt9m111_reg_mask(client, MT9M111_EFFECTS_MODE,
> > > +					 colorfx[i].value,
> > > +					 MT9M111_EFFECTS_MODE_MASK);
> > > +			return 0;
> > >  		}
> > >  	}
> > >
> > > @@ -890,29 +894,41 @@ static int mt9m111_s_ctrl(struct v4l2_ctrl *ctrl)
> > >  {
> > >  	struct mt9m111 *mt9m111 = container_of(ctrl->handler,
> > >  					       struct mt9m111, hdl);
> > > +	int ret;
> > >
> > >  	switch (ctrl->id) {
> > >  	case V4L2_CID_VFLIP:
> > > -		return mt9m111_set_flip(mt9m111, ctrl->val,
> > > -					MT9M111_RMB_MIRROR_ROWS);
> > > +		ret = mt9m111_set_flip(mt9m111, ctrl->val,
> > > +				       MT9M111_RMB_MIRROR_ROWS);
> > > +		break;
> > >  	case V4L2_CID_HFLIP:
> > > -		return mt9m111_set_flip(mt9m111, ctrl->val,
> > > -					MT9M111_RMB_MIRROR_COLS);
> > > +		ret = mt9m111_set_flip(mt9m111, ctrl->val,
> > > +				       MT9M111_RMB_MIRROR_COLS);
> > > +		break;
> > >  	case V4L2_CID_GAIN:
> > > -		return mt9m111_set_global_gain(mt9m111, ctrl->val);
> > > +		ret = mt9m111_set_global_gain(mt9m111, ctrl->val);
> > > +		break;
> > >  	case V4L2_CID_EXPOSURE_AUTO:
> > > -		return mt9m111_set_autoexposure(mt9m111, ctrl->val);
> > > +		ret = mt9m111_set_autoexposure(mt9m111, ctrl->val);
> > > +		break;
> > >  	case V4L2_CID_AUTO_WHITE_BALANCE:
> > > -		return mt9m111_set_autowhitebalance(mt9m111, ctrl->val);
> > > +		ret = mt9m111_set_autowhitebalance(mt9m111, ctrl->val);
> > > +		break;
> > >  	case V4L2_CID_TEST_PATTERN:
> > > -		return mt9m111_set_test_pattern(mt9m111, ctrl->val);
> > > +		ret = mt9m111_set_test_pattern(mt9m111, ctrl->val);
> > > +		break;
> > >  	case V4L2_CID_COLORFX:
> > > -		return mt9m111_set_colorfx(mt9m111, ctrl->val);
> > > +		ret = mt9m111_set_colorfx(mt9m111, ctrl->val);
> > > +		break;
> > >  	case V4L2_CID_PIXEL_RATE:
> > > -		return 0;
> > > +		ret = 0;
> > > +		break;
> > > +	default:
> > > +		ret = -EINVAL;
> > >  	}
> > >
> > > -	return -EINVAL;
> > > +
> > > +	return ret;
> > >  }
> > >
> > >  static int mt9m111_suspend(struct mt9m111 *mt9m111)
> > > --
> > > 2.30.2
> > >
> >