Re: [i-g-t,5/6] tests/kms_feature_discovery: add basic usb4 switch discovery

["Murthy, Arun R" <arun.r.murthy@intel.com>]

On 26-02-2026 02:58, Kunal Joshi wrote:
> Add a 'usb4-switch' subtest that verifies the Microsoft USB4 Switch
> 3141 is reachable. The test initializes the switch library and queries
> the active port to confirm communication works.
>
> This enables CI to detect when USB4 switch hardware is available
> before running the full kms_usb4_switch test suite.
>
> Signed-off-by: Kunal Joshi <kunal1.joshi@intel.com>
Looks good to me

Reviewed-by: Arun R Murthy <arun.r.murthy@intel.com>

Thanks and Regards,
Arun R Murthy
--------------------

> ---
>   tests/kms_feature_discovery.c | 23 +++++++++++++++++++++++
>   1 file changed, 23 insertions(+)
>
> diff --git a/tests/kms_feature_discovery.c b/tests/kms_feature_discovery.c
> index f0216a4ce..b05055186 100644
> --- a/tests/kms_feature_discovery.c
> +++ b/tests/kms_feature_discovery.c
> @@ -40,6 +40,7 @@
>   #include "igt_psr.h"
>   #include "igt_sysfs.h"
>   #include "igt_types.h"
> +#include "igt_usb4_switch.h"
>   
>   /**
>    * SUBTEST: display
> @@ -63,6 +64,9 @@
>    * SUBTEST: dp-mst
>    * Description: Make sure that we have DP-MST configuration.
>    *
> + * SUBTEST: usb4-switch
> + * Description: Verify that USB4 Switch 3141 is available and responding.
> + *
>    * arg[1].values: 1, 2, 3, 4
>    */
>   
> @@ -147,6 +151,25 @@ int igt_main() {
>   		}
>   #endif
>   
> +		igt_describe("Verify that USB4 Switch 3141 is available and responding.");
> +		igt_subtest("usb4-switch") {
> +			struct usb4switch *sw;
> +			int port;
> +
> +			sw = usb4switch_init(fd);
> +			igt_require_f(sw,
> +				      "USB4 Switch 3141 not available\n");
> +
> +			/* Verify communication works by querying active port */
> +			port = usb4switch_get_active_port(sw);
> +			igt_assert_f(port >= 0,
> +				     "Cannot communicate with USB4 switch\n");
> +
> +			igt_info("USB4 Switch 3141 available (active port: %d)\n",
> +				 port);
> +			usb4switch_deinit(sw);
> +		}
> +
>   		igt_describe("Make sure that we have eDP panel with PSR1 support.");
>   		igt_subtest("psr1") {
>   			igt_require(psr_sink_support(fd, debugfs_fd, PSR_MODE_1, NULL));