Re: [PATCH 2/4] media: mt9m111: fix subdev API usage

From: Sakari Ailus
Date: Mon Aug 22 2022 - 02:29:18 EST

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.
>
> Signed-off-by: Marco Felsch <m.felsch@xxxxxxxxxxxxxx>
> ---
> 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);

If the function can fail, it'd be much better to move it to s_stream
callback than ignore the error.

Same for the rest of such changes.

> + 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;

These were just fine.

> }
>
> - return -EINVAL;
> +
> + return ret;
> }
>
> static int mt9m111_suspend(struct mt9m111 *mt9m111)

--
Regards,

Sakari Ailus