On 10/06/2024 11:11, Laurent Pinchart wrote:
> Hi Hans,
>
> On Mon, Jun 10, 2024 at 11:06:30AM +0200, Hans Verkuil wrote:
>> On 10/06/2024 11:00, Laurent Pinchart wrote:
>>> On Mon, Jun 10, 2024 at 09:14:59AM +0300, Tomi Valkeinen wrote:
>>>> On 10/06/2024 04:22, Laurent Pinchart wrote:
>>>>> Add a -W/--which argument to media-ctl to select which state to operate
>>>>> on. Default to the ACTIVE state to preserve the current behaviour.
>>>>>
>>>>> Despite the fact that all values set on the TRY state are lost when
>>>>> media-ctl terminates, support for the TRY state is useful in order to
>>>>> retrieve the default configuration of subdevs, or to try configurations.
>>>>
>>>> I think this is fine, but I'm curious why you chose such an argument. I
>>>> would have thought "-t/--try" (or even just --try) would have been
>>>> simpler to implement and to use. I think I would remember "--try"
>>>> easily, but "-W TRY", I fear I'll have to check the man page every time...
>>>
>>> There are a few reasons:
>>>
>>> - Be closer to the API (media-ctl is a low-level tool)
>>> - Support other values later if the kernel API evolves (no plan for
>>> that, but who knows ?)
>>> - I find it easier to propagate arguments in scripts this way. If a
>>> script that wraps media-ctl receives a nothing/--try argument, it's
>>> fairly easy to translate that to nothing/-W TRY. If it receives a
>>> --foo ACTIVE/TRY argument (on the command line, in an interactive
>>> prompt, as part of a string that tells what to do on a pad, ...), then
>>> translating that to '-W arg' is easier than to nothing/-W TRY.
>>>
>>>>> Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
>>>>> ---
>>>>> utils/media-ctl/media-ctl.c | 13 +++++++------
>>>>> utils/media-ctl/options.c | 18 +++++++++++++++++-
>>>>> utils/media-ctl/options.h | 1 +
>>>>> 3 files changed, 25 insertions(+), 7 deletions(-)
>>>>>
>>>>> diff --git a/utils/media-ctl/media-ctl.c b/utils/media-ctl/media-ctl.c
>>>>> index 42b1bd9aaa6e..33df0880fd9b 100644
>>>>> --- a/utils/media-ctl/media-ctl.c
>>>>> +++ b/utils/media-ctl/media-ctl.c
>>>>> @@ -600,7 +600,6 @@ static void media_print_topology_text(struct media_device *media,
>>>>>
>>>>> int main(int argc, char **argv)
>>>>> {
>>>>> - const enum v4l2_subdev_format_whence which = V4L2_SUBDEV_FORMAT_ACTIVE;
>>>>> struct media_device *media;
>>>>> struct media_entity *entity = NULL;
>>>>> int ret = -1;
>>>>> @@ -667,7 +666,8 @@ int main(int argc, char **argv)
>>>>> goto out;
>>>>> }
>>>>>
>>>>> - v4l2_subdev_print_format(pad->entity, pad->index, stream, which);
>>>>> + v4l2_subdev_print_format(pad->entity, pad->index, stream,
>>>>> + media_opts.which);
>>>>> }
>>>>>
>>>>> if (media_opts.get_dv_pad) {
>>>>> @@ -709,9 +709,10 @@ int main(int argc, char **argv)
>>>>> media_print_topology_dot(media);
>>>>> } else if (media_opts.print) {
>>>>> if (entity)
>>>>> - media_print_topology_text_entity(media, entity, which);
>>>>> + media_print_topology_text_entity(media, entity,
>>>>> + media_opts.which);
>>>>> else
>>>>> - media_print_topology_text(media, which);
>>>>> + media_print_topology_text(media, media_opts.which);
>>>>> } else if (entity) {
>>>>> const char *devname;
>>>>>
>>>>> @@ -741,7 +742,7 @@ int main(int argc, char **argv)
>>>>> }
>>>>>
>>>>> if (media_opts.routes) {
>>>>> - ret = v4l2_subdev_parse_setup_routes(media, which,
>>>>> + ret = v4l2_subdev_parse_setup_routes(media, media_opts.which,
>>>>> media_opts.routes);
>>>>> if (ret) {
>>>>> printf("Unable to setup routes: %s (%d)\n",
>>>>> @@ -751,7 +752,7 @@ int main(int argc, char **argv)
>>>>> }
>>>>>
>>>>> if (media_opts.formats) {
>>>>> - ret = v4l2_subdev_parse_setup_formats(media, which,
>>>>> + ret = v4l2_subdev_parse_setup_formats(media, media_opts.which,
>>>>> media_opts.formats);
>>>>> if (ret) {
>>>>> printf("Unable to setup formats: %s (%d)\n",
>>>>> diff --git a/utils/media-ctl/options.c b/utils/media-ctl/options.c
>>>>> index 3c408a1b9b06..3606525c33da 100644
>>>>> --- a/utils/media-ctl/options.c
>>>>> +++ b/utils/media-ctl/options.c
>>>>> @@ -40,6 +40,7 @@
>>>>>
>>>>> struct media_options media_opts = {
>>>>> .devname = MEDIA_DEVNAME_DEFAULT,
>>>>> + .which = V4L2_SUBDEV_FORMAT_ACTIVE,
>>>>> };
>>>>>
>>>>> static void print_version()
>>>>> @@ -75,6 +76,7 @@ static void usage(const char *argv0)
>>>>> printf("-r, --reset Reset all links to inactive\n");
>>>>> printf("-v, --verbose Be verbose\n");
>>>>> printf(" --version Show version information\n");
>>>>> + printf("-W, --which which Select the subdev state to operate on\n");
>>>>> printf("\n");
>>>>> printf("Links and formats are defined as\n");
>>>>> printf("\tlinks = link { ',' link } ;\n");
>>>>> @@ -140,6 +142,8 @@ static void usage(const char *argv0)
>>>>> for (i = V4L2_YCBCR_ENC_DEFAULT; i <= V4L2_YCBCR_ENC_SMPTE240M; i++)
>>>>> printf("\t %s\n",
>>>>> v4l2_subdev_ycbcr_encoding_to_string(i));
>>>>> +
>>>>> + printf("\twhich Subdev state ('ACTIVE' or 'TRY')\n");
>>>>> }
>>>>>
>>>>> #define OPT_PRINT_DOT 256
>>>>> @@ -168,6 +172,7 @@ static struct option opts[] = {
>>>>> {"reset", 0, 0, 'r'},
>>>>> {"verbose", 0, 0, 'v'},
>>>>> {"version", 0, 0, OPT_VERSION},
>>>>> + {"which", 1, 0, 'W'},
>>>>> { },
>>>>> };
>>>>>
>>>>> @@ -244,7 +249,7 @@ int parse_cmdline(int argc, char **argv)
>>>>> }
>>>>>
>>>>> /* parse options */
>>>>> - while ((opt = getopt_long(argc, argv, "d:e:f:hil:prvV:R:",
>>>>> + while ((opt = getopt_long(argc, argv, "d:e:f:hil:prvV:R:W:",
>>>>> opts, NULL)) != -1) {
>>>>> switch (opt) {
>>>>> case 'd':
>>>>> @@ -294,6 +299,17 @@ int parse_cmdline(int argc, char **argv)
>>>>> media_opts.routes = optarg;
>>>>> break;
>>>>>
>>>>> + case 'W':
>>>>> + if (!strcmp(optarg, "ACTIVE"))
>>>>> + media_opts.which = V4L2_SUBDEV_FORMAT_ACTIVE;
>>>>> + else if (!strcmp(optarg, "TRY"))
>>>>> + media_opts.which = V4L2_SUBDEV_FORMAT_TRY;
>>
>> I very much prefer lower case here since it is a pain to type otherwise.
>> Alternatively, make this a case-insensitive string compare, that's fine as well.
>
> I've tried to stick to the kernel API, the same way we use upper-case
> media bus codes. If it's generally preferred to use lower-case strings,
> or make the comparison case-insensitive, I can do that too. I generally
> dislike case-insensitivity though, it can easily lead to confusion.
Looking at 'media-ctl -h' it uses lower-case for pretty much everything,
including v4l2-field, v4l2-colorspace, etc. So if this is suddenly uppercase,
then that is inconsistent with the other options of this utility.
Note that I keep everything lowercase in v4l2-ctl/compliance as well.
Regards,
Hans
>
>>>>> + else {
>>>>> + printf("Invalid 'which' value '%s'\n", optarg);
>>>>> + return 1;
>>>>> + }
>>>>> + break;
>>>>> +
>>>>> case OPT_PRINT_DOT:
>>>>> media_opts.print_dot = 1;
>>>>> break;
>>>>> diff --git a/utils/media-ctl/options.h b/utils/media-ctl/options.h
>>>>> index 753d09347585..095729b98014 100644
>>>>> --- a/utils/media-ctl/options.h
>>>>> +++ b/utils/media-ctl/options.h
>>>>> @@ -37,6 +37,7 @@ struct media_options
>>>>> const char *get_dv_pad;
>>>>> const char *dv_pad;
>>>>> const char *routes;
>>>>> + enum v4l2_subdev_format_whence which;
>>>>> };
>>>>>
>>>>> extern struct media_options media_opts;
>
