Re: [PATCH 4/4 v2][FOR 3.1] v4l2: add blackfin capture bridge driver

[Scott Jiang <scott.jiang.linux@gmail.com>]

>
>> +             ret = v4l2_subdev_call(bcap_dev->sd, video,
>> +                                     g_mbus_fmt, &mbus_fmt);
>> +             if (ret < 0)
>> +                     return ret;
>> +
>> +             for (i = 0; i < BCAP_MAX_FMTS; i++) {
>> +                     if (mbus_fmt.code != bcap_formats[i].mbus_code)
>> +                             continue;
>> +                     bcap_fmt = &bcap_formats[i];
>> +                     v4l2_fill_pix_format(pixfmt, &mbus_fmt);
>> +                     pixfmt->pixelformat = bcap_fmt->pixelformat;
>> +                     pixfmt->bytesperline = pixfmt->width * bcap_fmt->bpp / 8;
>> +                     pixfmt->sizeimage = pixfmt->bytesperline * pixfmt->height;
>> +                     break;
>> +             }
>> +             if (i == BCAP_MAX_FMTS) {
>> +                     v4l2_err(&bcap_dev->v4l2_dev,
>> +                                     "subdev fmt is not supported by bcap\n");
>> +                     return -EINVAL;
>> +             }
>
> Why do this on first open? Shouldn't it be better to do this after the subdev
> was loaded?
>
Hi Hans, thank you for your comments.
This point I haven't had a good solution. PPI is only a parallel port,
it has no default std or format.
That's why you always found I have no default std and format.
Sylwester Nawrocki recommend me add this code here, but different
input can has different std and format according to v4l2 spec.
That means if app only set input, or set input and std without setting
format, the default format getting here may be invalid.
Do you have any better solution for this?