Re: [PATCH v9 2/2] tests/kms_vrr: add support for full range refresh rate testing

["Naladala, Ramanaidu" <Ramanaidu.naladala@intel.com>]

Hi Shawn,

On 6/17/2026 12:18 PM, Lee Shawn C wrote:
> Currently, kms_vrr tests fixed step increments within the VRR range.
> To better validate hardware stability and potential issues across the
> entire spectrum, this patch adds a 'full-range' testing mode.
>
> When the full-range flag is enabled, the test will:
> 1. Iterate from the maximum to the minimum refresh rate (stepping by 1).
> 2. For standard testing, maintain the existing behavior of incrementing
>     from minimum to maximum using the defined step size.
>
> v2: Fix build failure by adding documentation for the new subtest.
> v3: Remove unnecessary '!!' operator when assigning to bool.
> v4: Add full-range (top-down/bottom-up) subtests to verify all supported
>      RR within VRR range.
> v5: Fix build failure for the new subtest.
> v6: Revert commit 862eb176244f ("tests/kms_vrr: Start virtual RR test
>      above midpoint to avoid mode fallback").
> v7: Not allow to run full range test if eDP display did not support
>      multiple refresh rate.
> v8: Add is_pixel_clock_identical() helper.
> v9: Add ALLOW_MODESET flag to the initial commit request.
>
> Cc: Naladala Ramanaidu <ramanaidu.naladala@intel.com>
> Signed-off-by: Lee Shawn C <shawn.c.lee@intel.com>
> ---
>   tests/kms_vrr.c | 175 +++++++++++++++++++++++++++++++++++++++---------
>   1 file changed, 142 insertions(+), 33 deletions(-)
>
> diff --git a/tests/kms_vrr.c b/tests/kms_vrr.c
> index 8f5c4a7c1501..ad9e4e4757f7 100644
> --- a/tests/kms_vrr.c
> +++ b/tests/kms_vrr.c
> @@ -62,9 +62,11 @@
>    * Description: Test to switch RR seamlessly without modeset.
>    * Mega feature: General Display Features
>    *
> - * SUBTEST: seamless-rr-switch-virtual
> - * Description: Test to create a Virtual Mode in VRR range and switch to it
> - * 		without a full modeset.
> + * SUBTEST: seamless-rr-switch-virtual-top-down
> + * Description: Vrr seamless refresh rate switch for virtual modes using full range
> + *
> + * SUBTEST: seamless-rr-switch-virtual-bottom-up
> + * Description: Vrr seamless refresh rate switch for virtual modes using full range
>    *
>    * SUBTEST: lobf
>    * Description: Test to validate link-off between active frames in non-psr
> @@ -93,9 +95,10 @@ enum {
>   	TEST_FLIPLINE = 1 << 3,
>   	TEST_SEAMLESS_VRR = 1 << 4,
>   	TEST_SEAMLESS_DRRS = 1 << 5,
> -	TEST_SEAMLESS_VIRTUAL_RR = 1 << 6,
> -	TEST_FASTSET = 1 << 7,
> -	TEST_MAXMIN = 1 << 8,
> +	TEST_SEAMLESS_VIRTUAL_RR_TOP_DOWN = 1 << 6,
> +	TEST_SEAMLESS_VIRTUAL_RR_BOTTOM_UP = 1 << 7,
> +	TEST_FASTSET = 1 << 8,
> +	TEST_MAXMIN = 1 << 9,
>   	TEST_LINK_OFF = 1 << 10,
>   	TEST_NEGATIVE = 1 << 11,
>   	TEST_FORCE_RR = 1 << 12,
> @@ -227,7 +230,7 @@ low_rr_mode_with_same_res(igt_output_t *output, unsigned int vrr_min)
>   	for (i = 0; i < connector->count_modes; i++)
>   		if (connector->modes[i].hdisplay == mode.hdisplay &&
>   		    connector->modes[i].vdisplay == mode.vdisplay &&
> -		    connector->modes[i].clock < mode.clock &&
> +		    connector->modes[i].clock <= mode.clock &&
>   		    connector->modes[i].vrefresh < mode.vrefresh &&
>   		    connector->modes[i].vrefresh >= vrr_min)
>   			mode = connector->modes[i];
> @@ -235,13 +238,93 @@ low_rr_mode_with_same_res(igt_output_t *output, unsigned int vrr_min)
>   	return mode;
>   }
>   
> -static void
> -virtual_rr_vrr_range_mode(drmModeModeInfo *mode, float virtual_refresh_rate)
> +static bool
> +virtual_rr_vrr_range_mode(data_t *data, drmModeModeInfo *mode, float virtual_refresh_rate)
>   {
>   	uint64_t clock_hz = mode->clock * 1000;
> +	uint16_t virtual_vtotal;
>   
> -	mode->vtotal = clock_hz / (mode->htotal * virtual_refresh_rate);
> +	virtual_vtotal = clock_hz / (mode->htotal * virtual_refresh_rate);
> +	if (is_intel_device(data->drm_fd) && virtual_vtotal > 8192) {
> +		igt_info("VTotal (%d) already exceed 8192 at %fHz\n",
> +			 virtual_vtotal, virtual_refresh_rate);
> +		return false;
> +	}
> +
> +	mode->vsync_start = virtual_vtotal - (mode->vtotal - mode->vsync_start);
> +	mode->vsync_end   = virtual_vtotal - (mode->vtotal - mode->vsync_end);
> +	mode->vtotal = virtual_vtotal;
>   	mode->vrefresh = virtual_refresh_rate;
> +	return true;
> +}
> +
> +static bool
> +is_edp_multiple_rr_panel(igt_output_t *output)
> +{
> +	drmModeConnector *connector = output->config.connector;
> +	uint32_t first_clock = 0, first_rr = 0;
> +	bool found_first = false;
> +
> +	if (connector->connector_type != DRM_MODE_CONNECTOR_eDP) {
> +		igt_info("Connector %s is not eDP, skipping DRRS check\n",
> +			 output->name);
> +		return false;
> +	}
> +
> +	for (int i = 0; i < connector->count_modes; i++) {
> +		drmModeModeInfo *mode = &connector->modes[i];
> +
> +		if (!found_first) {
> +			first_clock = mode->clock;
> +			first_rr    = mode->vrefresh;
> +			found_first = true;
> +			continue;
> +		}
> +
> +		if (mode->vrefresh != first_rr &&
> +		    mode->clock == first_clock) {
> +			igt_info("Multiple RR panel detected (not DRRS): "
> +				 "same clock %d kHz, vrefresh %d vs %d Hz\n",
> +				 first_clock, first_rr, mode->vrefresh);
> +			return true;
> +		}
> +	}
> +
> +	return false;
> +}
> +
> +static drmModeModeInfo*
> +get_selected_fixed_mode(igt_output_t *output, bool lowest)
> +{
> +	drmModeConnectorPtr connector = output->config.connector;
> +	drmModeModeInfo *selected_mode = NULL;
> +
> +	for (int i = 0; i < connector->count_modes; i++) {
> +		drmModeModeInfo *m = &connector->modes[i];
> +
> +		if (m->type & (DRM_MODE_TYPE_PREFERRED | DRM_MODE_TYPE_DRIVER)) {
> +			if (!selected_mode) {
> +				selected_mode = m;
> +				continue;
> +			}
> +
> +			if (lowest) {
> +				if (m->vrefresh < selected_mode->vrefresh)
> +					selected_mode = m;
> +			} else {
> +				if (m->vrefresh > selected_mode->vrefresh)
> +					selected_mode = m;
> +			}
> +		}
> +	}
> +
> +	if (selected_mode) {
> +		igt_info("Found Target Fixed Mode: \"%s\" %dHz (vtotal: %d)\n",
> +			 selected_mode->name, selected_mode->vrefresh, selected_mode->vtotal);
> +		return selected_mode;
> +	}
> +
> +	return NULL;
>   }
>   
>   /* Read min and max vrr range from the connector debugfs. */
> @@ -754,45 +837,65 @@ test_seamless_virtual_rr_basic(data_t *data, igt_crtc_t *crtc,
>   			       igt_output_t *output, uint32_t flags)
>   {
>   	uint32_t result;
> -	unsigned int vrefresh;
> +	int vrefresh;
>   	uint64_t rate[] = {0};
> -	uint32_t step_size;
> -	drmModeModeInfo virtual_mode;
> +	int start, end, step;
> +	drmModeModeInfo *virtual_mode = NULL;
> +	bool need_low_rr = flags & TEST_SEAMLESS_VIRTUAL_RR_BOTTOM_UP;
>   
> -	igt_info("Use HIGH_RR Mode as default\n");
> -	kmstest_dump_mode(&data->switch_modes[HIGH_RR_MODE]);
> +	if (!is_edp_multiple_rr_panel(output)) {
> +		igt_info("This panel does not support this testing.\n");
> +		return;
> +	}
When clocks are different you can skip 
seamless-rr-switch-virtual-bottom-up subtest.

apart from this remaining all looks good to me.
> +
> +	virtual_mode = get_selected_fixed_mode(output, need_low_rr);
> +	if (!virtual_mode)
> +		return;
> +
> +	igt_info("Use %s_RR Mode as default\n", need_low_rr ? "LOW" : "HIGH");
> +	kmstest_dump_mode(virtual_mode);
>   
>   	prepare_test(data, output, crtc);
> -	rate[0] = igt_kms_frame_time_from_vrefresh(data->switch_modes[HIGH_RR_MODE].vrefresh);
> +	rate[0] = igt_kms_frame_time_from_vrefresh(virtual_mode->vrefresh);
>   
>   	/*
>   	 * Sink with DRR and VRR can be in downclock mode so
> -	 * switch to highest refresh rate mode.
> +	 * switch to desired requested rate mode.
>   	 */
> -	igt_output_override_mode(output, &data->switch_modes[HIGH_RR_MODE]);
> -	igt_assert(igt_display_try_commit_atomic(&data->display, DRM_MODE_PAGE_FLIP_EVENT, NULL) == 0);
> +	igt_output_override_mode(output, virtual_mode);
> +	igt_assert(igt_display_try_commit_atomic(&data->display,
> +						 DRM_MODE_PAGE_FLIP_EVENT |
> +						 DRM_MODE_ATOMIC_ALLOW_MODESET,
> +						 NULL) == 0);
>   
>   	result = flip_and_measure(data, output, rate, 1, TEST_DURATION_NS);
>   	igt_assert_f(result > 75,
>   		     "Refresh rate (%u Hz) %"PRIu64"ns: Target threshold not reached, result was %u%%\n",
>   		     data->switch_modes[HIGH_RR_MODE].vrefresh, rate[0], result);
>   
> -	/*
> -	 * Calculate step size by considering the no. of steps required to
> -	 * reach Vmin to Vmax as 5.
> -	 */
> -	step_size = (data->range.max - data->range.min) / 5;
> -
>   	/* Switch to Virtual RR */
> -	virtual_mode = *igt_output_get_mode(output);
> +	virtual_mode = igt_output_get_mode(output);
> +
> +	if (flags & TEST_SEAMLESS_VIRTUAL_RR_TOP_DOWN) {
> +		start = data->range.max;
> +		end = data->range.min;
> +		step = -1;
> +	} else {
> +		start = data->range.min;
> +		end = data->range.max;
> +		step = 1;
> +	}
>   
> -	for (vrefresh = data->range.min + step_size; vrefresh < data->range.max; vrefresh += step_size) {
> -		virtual_rr_vrr_range_mode(&virtual_mode, vrefresh);
> +	for (vrefresh = start; step > 0 ? vrefresh <= end : vrefresh >= end; vrefresh += step) {
> +		if (!virtual_rr_vrr_range_mode(data, virtual_mode, vrefresh))
> +			continue;
>   
>   		igt_info("Requesting Virtual Mode with Refresh Rate (%u Hz): \n", vrefresh);
> -		kmstest_dump_mode(&virtual_mode);
> +		kmstest_dump_mode(virtual_mode);
> +
> +		igt_output_override_mode(output, virtual_mode);
>   
> -		igt_output_override_mode(output, &virtual_mode);
> +		igt_assert(igt_display_try_commit_atomic(&data->display, DRM_MODE_ATOMIC_TEST_ONLY, NULL) == 0);
>   		igt_assert(igt_display_try_commit_atomic(&data->display, 0, NULL) == 0);
>   
>   		rate[0] = igt_kms_frame_time_from_vrefresh(vrefresh);
> @@ -1092,9 +1195,15 @@ int igt_main_args("drs:", long_opts, help_str, opt_handler, &data)
>   		igt_subtest_with_dynamic("flip-basic-fastset")
>   			run_vrr_test(&data, test_basic, TEST_FASTSET);
>   
> -		igt_describe("Test to switch to any custom virtual mode in VRR range without modeset.");
> -		igt_subtest_with_dynamic("seamless-rr-switch-virtual")
> -			run_vrr_test(&data, test_seamless_virtual_rr_basic, TEST_SEAMLESS_VIRTUAL_RR);
> +		igt_describe("Test to switch to all virtual modes in VRR range without modeset.");
> +		igt_subtest_with_dynamic("seamless-rr-switch-virtual-top-down")
> +			run_vrr_test(&data, test_seamless_virtual_rr_basic,
> +				     TEST_SEAMLESS_VIRTUAL_RR_TOP_DOWN);
> +
> +		igt_describe("Test to switch to all virtual modes in VRR range without modeset.");
> +		igt_subtest_with_dynamic("seamless-rr-switch-virtual-bottom-up")
> +			run_vrr_test(&data, test_seamless_virtual_rr_basic,
> +				     TEST_SEAMLESS_VIRTUAL_RR_BOTTOM_UP);
>   
>   		igt_describe("Test to validate the link-off between active frames in "
>   			     "non-PSR operation.");