Hi Tomasz and Andy,
On Sat, Mar 03, 2018 at 12:43:59AM +0900, Tomasz Figa wrote:
...
> > +static int imx258_set_ctrl(struct v4l2_ctrl *ctrl)
> > +{
> > + struct imx258 *imx258 =
> > + container_of(ctrl->handler, struct imx258, ctrl_handler);
> > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
> > + int ret = 0;
> > + /*
> > + * Applying V4L2 control value only happens
> > + * when power is up for streaming
> > + */
> > + if (pm_runtime_get_if_in_use(&client->dev) <= 0)
> > + return 0;
>
> I thought we decided to fix this to handle disabled runtime PM properly.
Good point. I bet this is a problem in a few other drivers, too. How would
you fix that? Check for zero only?
...
> [snip]
> > +/* Initialize control handlers */
> > +static int imx258_init_controls(struct imx258 *imx258)
> > +{
> > + struct i2c_client *client = v4l2_get_subdevdata(&imx258->sd);
> > + struct v4l2_ctrl_handler *ctrl_hdlr;
> > + s64 exposure_max;
> > + s64 vblank_def;
> > + s64 vblank_min;
> > + s64 pixel_rate_min;
> > + s64 pixel_rate_max;
> > + int ret;
> > +
> > + ctrl_hdlr = &imx258->ctrl_handler;
> > + ret = v4l2_ctrl_handler_init(ctrl_hdlr, 8);
> > + if (ret)
>
> Missing error message.
>
> > + return ret;
> > +
> > + mutex_init(&imx258->mutex);
> > + ctrl_hdlr->lock = &imx258->mutex;
> > + imx258->link_freq = v4l2_ctrl_new_int_menu(ctrl_hdlr,
> > + &imx258_ctrl_ops,
> > + V4L2_CID_LINK_FREQ,
> > + ARRAY_SIZE(link_freq_menu_items) - 1,
> > + 0,
> > + link_freq_menu_items);
> > +
> > + if (!imx258->link_freq) {
> > + ret = -EINVAL;
>
> Missing error message.
I wouldn't add an error message here. Typically you'd need that information
at development time only, never after that. v4l2_ctrl_new_int_menu(), as
other control framework functions creating new controls, can fail due to
memory allocation failure (which is already vocally reported) or due to bad
parameters (that are constants).
I'd rather do:
if (!imx258->link_freq)
... |= ...;
It simplifies error handling and removes the need for goto.
>
> > + goto error;
> > + }
> > +
> > + imx258->link_freq->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> > + pixel_rate_max = link_freq_to_pixel_rate(link_freq_menu_items[0]);
> > + pixel_rate_min = link_freq_to_pixel_rate(link_freq_menu_items[1]);
> > + /* By default, PIXEL_RATE is read only */
> > + imx258->pixel_rate = v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops,
> > + V4L2_CID_PIXEL_RATE,
> > + pixel_rate_min, pixel_rate_max,
> > + 1, pixel_rate_max);
> > +
> > +
> > + vblank_def = imx258->cur_mode->vts_def - imx258->cur_mode->height;
> > + vblank_min = imx258->cur_mode->vts_min - imx258->cur_mode->height;
> > + imx258->vblank = v4l2_ctrl_new_std(
> > + ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_VBLANK,
> > + vblank_min,
> > + IMX258_VTS_MAX - imx258->cur_mode->height, 1,
> > + vblank_def);
> > +
> > + imx258->hblank = v4l2_ctrl_new_std(
> > + ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_HBLANK,
> > + IMX258_PPL_650MHZ - imx258->cur_mode->width,
> > + IMX258_PPL_650MHZ - imx258->cur_mode->width,
> > + 1,
> > + IMX258_PPL_650MHZ - imx258->cur_mode->width);
> > +
> > + if (!imx258->hblank) {
> > + ret = -EINVAL;
> > + goto error;
> > + }
>
> Why checking hblank, but not other controls? I think in this case just
> the general check for ctrl_hdlr->error should be enough.
There's no need to access most other controls (except blank and link_freq).
The flags field is set for hblank below, therefore the check.
>
> > +
> > + imx258->hblank->flags |= V4L2_CTRL_FLAG_READ_ONLY;
> > +
> > + exposure_max = imx258->cur_mode->vts_def - 8;
> > + imx258->exposure = v4l2_ctrl_new_std(
> > + ctrl_hdlr, &imx258_ctrl_ops,
> > + V4L2_CID_EXPOSURE, IMX258_EXPOSURE_MIN,
> > + IMX258_EXPOSURE_MAX, IMX258_EXPOSURE_STEP,
> > + IMX258_EXPOSURE_DEFAULT);
> > +
> > + v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_ANALOGUE_GAIN,
> > + IMX258_ANA_GAIN_MIN, IMX258_ANA_GAIN_MAX,
> > + IMX258_ANA_GAIN_STEP, IMX258_ANA_GAIN_DEFAULT);
> > +
> > + v4l2_ctrl_new_std(ctrl_hdlr, &imx258_ctrl_ops, V4L2_CID_DIGITAL_GAIN,
> > + IMX258_DGTL_GAIN_MIN, IMX258_DGTL_GAIN_MAX,
> > + IMX258_DGTL_GAIN_STEP, IMX258_DGTL_GAIN_DEFAULT);
> > +
> > + v4l2_ctrl_new_std_menu_items(ctrl_hdlr, &imx258_ctrl_ops,
> > + V4L2_CID_TEST_PATTERN,
> > + ARRAY_SIZE(imx258_test_pattern_menu) - 1,
> > + 0, 0, imx258_test_pattern_menu);
> > +
> > + if (ctrl_hdlr->error) {
> > + ret = ctrl_hdlr->error;
> > + dev_err(&client->dev, "%s control init failed (%d)\n",
> > + __func__, ret);
> > + goto error;
> > + }
> > +
> > + imx258->sd.ctrl_handler = ctrl_hdlr;
> > +
> > + return 0;
> > +
> > +error:
> > + v4l2_ctrl_handler_free(ctrl_hdlr);
> > + mutex_destroy(&imx258->mutex);
> > +
> > + return ret;
> > +}
> > +
> > +static void imx258_free_controls(struct imx258 *imx258)
> > +{
> > + v4l2_ctrl_handler_free(imx258->sd.ctrl_handler);
> > + mutex_destroy(&imx258->mutex);
> > +}
> > +
> > +static int imx258_probe(struct i2c_client *client)
> > +{
> > + struct imx258 *imx258;
> > + int ret;
> > + u32 val = 0;
> > +
> > + device_property_read_u32(&client->dev, "clock-frequency", &val);
> > + if (val != 19200000)
>
> Would be nice to print some error.
>
> > + return -EINVAL;
> > +
> > + imx258 = devm_kzalloc(&client->dev, sizeof(*imx258), GFP_KERNEL);
> > + if (!imx258)
> > + return -ENOMEM;
> > +
> > + /* Initialize subdev */
> > + v4l2_i2c_subdev_init(&imx258->sd, client, &imx258_subdev_ops);
> > +
> > + /* Check module identity */
> > + ret = imx258_identify_module(imx258);
> > + if (ret)
> > + return ret;
> > +
> > + /* Set default mode to max resolution */
> > + imx258->cur_mode = &supported_modes[0];
> > +
> > + ret = imx258_init_controls(imx258);
> > + if (ret)
> > + return ret;
> > +
> > + /* Initialize subdev */
> > + imx258->sd.internal_ops = &imx258_internal_ops;
> > + imx258->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
> > + imx258->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
> > +
> > + /* Initialize source pad */
> > + imx258->pad.flags = MEDIA_PAD_FL_SOURCE;
> > +
> > + ret = media_entity_pads_init(&imx258->sd.entity, 1, &imx258->pad);
> > + if (ret) {
> > + dev_err(&client->dev, "%s failed:%d\n", __func__, ret);
>
> This isn't a very useful error message. "media_entity_pads_init()
> failed: %d\n" would make more sense.
Considering media_entity_pads_init() only fails due to bad parameters and
those would not change during the operation of the driver, IMO any error
message here is not useful.
--
Kind regards,
Sakari Ailus
sakari.ailus@xxxxxxxxxxxxxxx
