Re: v4l2-compliance does not pick media device with -z and -u options

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

On Thu, Jun 18, 2026 at 09:03:44AM +0200, Hans Verkuil wrote:
> Hi Laurent,
> 
> Here is a second attempt to fix this. Let me know if it works!
> 
> The reason is it so messy is that support for the media device and
> media bus info was added much later, and it really needs a cleanup.

I can't disagree :-) There are lots of opportunities to refactor the
code into classes with clear APIs.

> Anyway, fingers crossed...

It works better \o/

----------------------------------------
root@buildroot ~ # v4l2-compliance -z "platform:rkisp1" -u "imx219 1-0010"
v4l2-compliance 1.33.0-5476, 64 bits, 64-bit time_t
v4l2-compliance SHA: 1355f143676b 2026-06-18 06:31:21

Compliance test for rkisp1 device /dev/v4l-subdev3:

Driver Info:
        Driver version   : 7.1.0
        Capabilities     : 0x00000000
        Client Capabilities: 0x0000000000000003
streams interval-uses-which Media Driver Info:
        Driver name      : rkisp1
        Model            : rkisp1
        Serial           :
        Bus info         : platform:rkisp1
        Media version    : 7.1.0
        Hardware revision: 0x0000000e (14)
        Driver version   : 7.1.0
Interface Info:
        ID               : 0x0300002c
        Type             : V4L Sub-Device
Entity Info:
        ID               : 0x00000022 (34)
        Name             : imx219 1-0010
        Function         : Camera Sensor
        Pad 0x01000023   : 0: Source
          Link 0x02000024: to remote pad 0x100001e of entity 'csis-32e40000.csi' (Video Interface Bridge): Data

Required ioctls:
        test MC information (see 'Media Driver Info' above): OK
        test VIDIOC_SUDBEV_QUERYCAP: OK
        test invalid ioctls: OK

Allow for multiple opens:
        test second /dev/v4l-subdev3 open: OK
        test VIDIOC_SUBDEV_QUERYCAP: OK
        test for unlimited opens: OK

Debug ioctls:
        test VIDIOC_LOG_STATUS: OK (Not Supported)

Input ioctls:
        test VIDIOC_G/S_TUNER/ENUM_FREQ_BANDS: OK (Not Supported)
        test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
        test VIDIOC_S_HW_FREQ_SEEK: OK (Not Supported)
        test VIDIOC_ENUMAUDIO: OK (Not Supported)
        test VIDIOC_G/S/ENUMINPUT: OK (Not Supported)
        test VIDIOC_G/S_AUDIO: OK (Not Supported)
        Inputs: 0 Audio Inputs: 0 Tuners: 0

Output ioctls:
        test VIDIOC_G/S_MODULATOR: OK (Not Supported)
        test VIDIOC_G/S_FREQUENCY: OK (Not Supported)
        test VIDIOC_ENUMAUDOUT: OK (Not Supported)
        test VIDIOC_G/S/ENUMOUTPUT: OK (Not Supported)
        test VIDIOC_G/S_AUDOUT: OK (Not Supported)
        Outputs: 0 Audio Outputs: 0 Modulators: 0

Input/Output configuration ioctls:
        test VIDIOC_ENUM/G/S/QUERY_STD: OK (Not Supported)
        test VIDIOC_ENUM/G/S/QUERY_DV_TIMINGS: OK (Not Supported)
        test VIDIOC_DV_TIMINGS_CAP: OK (Not Supported)
        test VIDIOC_G/S_EDID: OK (Not Supported)

Sub-Device ioctls (Source Pad 0):
        Try Stream 0
        test Try VIDIOC_SUBDEV_ENUM_MBUS_CODE/FRAME_SIZE/FRAME_INTERVAL: OK
        test Try VIDIOC_SUBDEV_G/S_FMT: OK
                warn: v4l2-test-subdevs.cpp(566): VIDIOC_SUBDEV_G_SELECTION is supported for target 0 but not VIDIOC_SUBDEV_S_SELECTION
        test Try VIDIOC_SUBDEV_G/S_SELECTION/CROP: OK
        Active Stream 0
        test Active VIDIOC_SUBDEV_ENUM_MBUS_CODE/FRAME_SIZE/FRAME_INTERVAL: OK
        test Active VIDIOC_SUBDEV_G/S_FMT: OK
                warn: v4l2-test-subdevs.cpp(566): VIDIOC_SUBDEV_G_SELECTION is supported for target 0 but not VIDIOC_SUBDEV_S_SELECTION
        test Active VIDIOC_SUBDEV_G/S_SELECTION/CROP: OK
        test Active VIDIOC_SUBDEV_G/S_FRAME_INTERVAL: OK (Not Supported)

Control ioctls:
        test VIDIOC_QUERY_EXT_CTRL/QUERYMENU: OK
        test VIDIOC_QUERYCTRL: OK
        test VIDIOC_G/S_CTRL: OK
        test VIDIOC_G/S/TRY_EXT_CTRLS: OK
        test VIDIOC_(UN)SUBSCRIBE_EVENT/DQEVENT: OK
        test VIDIOC_G/S_JPEGCOMP: OK (Not Supported)
        Standard Controls: 20 Private Controls: 0

Format ioctls:
        test VIDIOC_ENUM_FMT/FRAMESIZES/FRAMEINTERVALS: OK (Not Supported)
        test VIDIOC_G/S_PARM: OK (Not Supported)
        test VIDIOC_G_FBUF: OK (Not Supported)
        test VIDIOC_G_FMT: OK (Not Supported)
        test VIDIOC_TRY_FMT: OK (Not Supported)
        test VIDIOC_S_FMT: OK (Not Supported)
        test VIDIOC_G_SLICED_VBI_CAP: OK (Not Supported)
        test Cropping: OK (Not Supported)
        test Composing: OK (Not Supported)
        test Scaling: OK (Not Supported)

Codec ioctls:
        test VIDIOC_(TRY_)ENCODER_CMD: OK (Not Supported)
        test VIDIOC_G_ENC_INDEX: OK (Not Supported)
        test VIDIOC_(TRY_)DECODER_CMD: OK (Not Supported)

Buffer ioctls:
        test VIDIOC_REQBUFS/CREATE_BUFS/QUERYBUF: OK (Not Supported)
        test CREATE_BUFS maximum buffers: OK
        test VIDIOC_REMOVE_BUFS: OK
        test VIDIOC_EXPBUF: OK (Not Supported)
        test Requests: OK (Not Supported)
        test blocking wait: OK (Not Supported)

Total for rkisp1 device /dev/v4l-subdev3: 54, Succeeded: 54, Failed: 0, Warnings: 2
----------------------------------------

I think we should skip quite a few of the bove tests for subdevs (the
"Format ioctls" and "Buffer ioctls" tests for instance), but that's a
separate issue.

Tested-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> diff --git a/utils/common/media-info.cpp b/utils/common/media-info.cpp
> index 95e4c74f..6d6d7904 100644
> --- a/utils/common/media-info.cpp
> +++ b/utils/common/media-info.cpp
> @@ -216,7 +216,7 @@ std::string mi_get_devpath_from_dev_t(dev_t dev)
>  	return devpath;
>  }
> 
> -int mi_get_media_fd(int fd, const char *bus_info)
> +int mi_get_media_fd(int fd)
>  {
>  	int media_fd = -1;
>  	dev_t dev;
> @@ -243,9 +243,39 @@ int mi_get_media_fd(int fd, const char *bus_info)
>  			devname += ep->d_name;
>  			media_fd = open(devname.c_str(), O_RDWR);
> 
> -			if (bus_info &&
> -			    (ioctl(media_fd, MEDIA_IOC_DEVICE_INFO, &mdinfo) ||
> -			     strcmp(mdinfo.bus_info, bus_info))) {
> +			if (ioctl(media_fd, MEDIA_IOC_DEVICE_INFO, &mdinfo)) {
> +				close(media_fd);
> +				continue;
> +			}
> +			break;
> +		}
> +	}
> +	closedir(dp);
> +	return media_fd;
> +}
> +
> +int mi_get_media_bus_info(const char *bus_info)
> +{
> +	int media_fd = -1;
> +	DIR *dp;
> +	struct dirent *ep;
> +
> +	if (!bus_info)
> +		return -1;
> +
> +	dp = opendir("/dev");
> +	if (dp == nullptr)
> +		return -1;
> +	while ((ep = readdir(dp))) {
> +		if (!memcmp(ep->d_name, "media", 5) && isdigit(ep->d_name[5])) {
> +			struct media_device_info mdinfo;
> +			std::string devname("/dev/");
> +
> +			devname += ep->d_name;
> +			media_fd = open(devname.c_str(), O_RDWR);
> +
> +			if (ioctl(media_fd, MEDIA_IOC_DEVICE_INFO, &mdinfo) ||
> +			    strcmp(mdinfo.bus_info, bus_info)) {
>  				close(media_fd);
>  				continue;
>  			}
> diff --git a/utils/common/media-info.h b/utils/common/media-info.h
> index c0dd6304..75eb29b4 100644
> --- a/utils/common/media-info.h
> +++ b/utils/common/media-info.h
> @@ -51,12 +51,15 @@ std::string mi_get_devpath_from_dev_t(dev_t dev);
> 
>  /*
>   * For a given device fd return the corresponding media device
> - * or -1 if there is none.
> - *
> - * If bus_info is not NULL, then find the media device that
> - * matches the given bus_info.
> + * or -1 if there is none. This only works if the media device
> + * is discoverable from where fd sits in /sys.
>   */
> -int mi_get_media_fd(int fd, const char *bus_info = NULL);
> +int mi_get_media_fd(int fd);
> +
> +/*
> + * Find the media device that matches the given bus_info.
> + */
> +int mi_get_media_bus_info(const char *bus_info);
> 
>  /* Return entity flags description */
>  std::string mi_entflags2s(__u32 flags);
> diff --git a/utils/v4l2-compliance/v4l2-compliance.cpp b/utils/v4l2-compliance/v4l2-compliance.cpp
> index 4e5c9d00..a04e4e84 100644
> --- a/utils/v4l2-compliance/v4l2-compliance.cpp
> +++ b/utils/v4l2-compliance/v4l2-compliance.cpp
> @@ -1007,7 +1007,7 @@ void testNode(struct node &node, struct node &node_m2m_cap, struct node &expbuf_
>  		if (parent_media_fd >= 0)
>  			media_fd = parent_media_fd;
>  		else
> -			media_fd = mi_get_media_fd(node.g_fd(), node.bus_info);
> +			media_fd = mi_get_media_bus_info(node.bus_info);
>  	}
> 
>  	int fd = node.is_media() ? node.g_fd() : media_fd;
> @@ -1658,6 +1658,7 @@ int main(int argc, char **argv)
>  	media_type type = MEDIA_TYPE_UNKNOWN;
>  	struct node expbuf_node;
>  	std::string media_bus_info;
> +	int media_fd = -1;
>  	const char *env_media_apps_color = getenv("MEDIA_APPS_COLOR");
> 
>  	/* command args */
> @@ -1903,6 +1904,16 @@ int main(int argc, char **argv)
>  			strerror(errno));
>  		std::exit(EXIT_FAILURE);
>  	}
> +	if (type != MEDIA_TYPE_MEDIA && !media_bus_info.empty()) {
> +		std::string media_devname;
> +
> +		media_fd = open_media_bus_info(media_bus_info, media_devname);
> +		if (media_fd < 0) {
> +			fprintf(stderr, "Failed to find media device for %s: %s\n",
> +				media_bus_info.c_str(), strerror(errno));
> +			std::exit(EXIT_FAILURE);
> +		}
> +	}
> 
>  	if (!expbuf_device.empty()) {
>  		expbuf_node.s_trace(options[OptTrace]);
> @@ -1915,7 +1926,7 @@ int main(int argc, char **argv)
>  		}
>  	}
> 
> -	testNode(node, node, expbuf_node, type, frame_count, all_fmt_frame_count);
> +	testNode(node, node, expbuf_node, type, frame_count, all_fmt_frame_count, media_fd);
> 
>  	if (!expbuf_device.empty())
>  		expbuf_node.close();
> diff --git a/utils/v4l2-compliance/v4l2-test-buffers.cpp b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> index 7e08668b..233cf03f 100644
> --- a/utils/v4l2-compliance/v4l2-test-buffers.cpp
> +++ b/utils/v4l2-compliance/v4l2-test-buffers.cpp
> @@ -2296,7 +2296,7 @@ int testDmaBuf(struct node *expbuf_node, struct node *node, struct node *node_m2
>  int testRequests(struct node *node, bool test_streaming)
>  {
>  	filehandles fhs;
> -	int media_fd = fhs.add(mi_get_media_fd(node->g_fd(), node->bus_info));
> +	int media_fd = fhs.add(mi_get_media_bus_info(node->bus_info));
>  	int req_fd;
>  	struct test_query_ext_ctrl valid_qctrl;
>  	v4l2_ext_controls ctrls;
> @@ -2432,7 +2432,7 @@ int testRequests(struct node *node, bool test_streaming)
>  	fail_on_test(doioctl_fd(req_fd, MEDIA_REQUEST_IOC_REINIT, nullptr) != EBADF);
> 
>  	// Open media_fd and alloc a request again
> -	media_fd = fhs.add(mi_get_media_fd(node->g_fd(), node->bus_info));
> +	media_fd = fhs.add(mi_get_media_bus_info(node->bus_info));
>  	fail_on_test(doioctl_fd(media_fd, MEDIA_IOC_REQUEST_ALLOC, &req_fd));
>  	fhs.add(req_fd);
>  	ctrls.count = 1;
> @@ -2507,7 +2507,7 @@ int testRequests(struct node *node, bool test_streaming)
>  	unsigned num_requests = 2 * num_bufs;
>  	last_seq.init();
> 
> -	media_fd = fhs.add(mi_get_media_fd(node->g_fd(), node->bus_info));
> +	media_fd = fhs.add(mi_get_media_bus_info(node->bus_info));
> 
>  	// Allocate the requests
>  	for (unsigned i = 0; i < num_requests; i++) {
> diff --git a/utils/v4l2-ctl/v4l2-ctl-streaming.cpp b/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
> index 517fc7f2..fe5d0dfe 100644
> --- a/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
> +++ b/utils/v4l2-ctl/v4l2-ctl-streaming.cpp
> @@ -1346,10 +1346,10 @@ static int do_setup_out_buffers(cv4l_fd &fd, cv4l_queue &q, FILE *fin, bool qbuf
>  		if (fmt.g_pixelformat() == V4L2_PIX_FMT_FWHT_STATELESS) {
>  			struct v4l2_capability vcap = {};
>  			fd.querycap(vcap);
> -			int media_fd = mi_get_media_fd(fd.g_fd(), (const char *)vcap.bus_info);
> +			int media_fd = mi_get_media_bus_info((const char *)vcap.bus_info);
> 
>  			if (media_fd < 0) {
> -				fprintf(stderr, "%s: mi_get_media_fd failed\n", __func__);
> +				fprintf(stderr, "%s: mi_get_media_bus_info failed\n", __func__);
>  				return media_fd;
>  			}
> 
> diff --git a/utils/v4l2-ctl/v4l2-ctl.cpp b/utils/v4l2-ctl/v4l2-ctl.cpp
> index 842e22fd..14f5c51f 100644
> --- a/utils/v4l2-ctl/v4l2-ctl.cpp
> +++ b/utils/v4l2-ctl/v4l2-ctl.cpp
> @@ -1382,7 +1382,10 @@ int main(int argc, char **argv)
>  			capabilities = vcap.device_caps;
>  	}
> 
> -	media_fd = mi_get_media_fd(fd, is_subdev ? 0 : (const char *)vcap.bus_info);
> +	if (is_subdev)
> +		media_fd = mi_get_media_fd(fd);

This won't work correctly on subdevs that are not direct children of the
device registering the media device, but it's fine, it's not a
regression. media_fd is only used to print the media info anyway, it
won't prevent anything else from working.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> +	else
> +		media_fd = mi_get_media_bus_info((const char *)vcap.bus_info);
> 
>  	priv_magic = (capabilities & V4L2_CAP_EXT_PIX_FORMAT) ?
>  			V4L2_PIX_FMT_PRIV_MAGIC : 0;
> 

-- 
Regards,

Laurent Pinchart