[igt-dev] [PATCH i-g-t 5/6] tests/i915/kms_dsc: Enable validation for VDSC Fractional BPP

[Swati Sharma <swati2.sharma@intel.com>]

Fractional BPP support comes from DSC1.2. To test Fractional BPP, debugfs entry
(force_dsc_fractional_bpp) is introduced. From the IGT; we are setting this
debugfs entry. However, before setting this debugfs entry, we are checking
capability i.e. Fractional BPP is supported by platform and sink both. In driver,
if force_dsc_fractional_bpp is set then while iterating over output bpp with
fractional step size we will continue if output_bpp is computed as integer and
allow DSC iff compressed bpp is fractional.

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
---
 tests/i915/kms_dsc.c | 91 ++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 87 insertions(+), 4 deletions(-)

diff --git a/tests/i915/kms_dsc.c b/tests/i915/kms_dsc.c
index 6a3eecdb4..a85066bb9 100644
--- a/tests/i915/kms_dsc.c
+++ b/tests/i915/kms_dsc.c
@@ -50,7 +50,8 @@ IGT_TEST_DESCRIPTION("Test to validate display stream compression");
 
 enum dsc_test_type {
 	TEST_DSC_BASIC,
-	TEST_DSC_BPC
+	TEST_DSC_BPC,
+	TEST_DSC_FRACTIONAL_BPP
 };
 
 enum dsc_output_format {
@@ -72,8 +73,10 @@ typedef struct {
 
 bool force_dsc_en_orig;
 bool force_dsc_ycbcr420_en_orig;
+bool force_dsc_fractional_bpp_en_orig;
 int force_dsc_restore_fd = -1;
 int force_dsc_ycbcr420_restore_fd = -1;
+int force_dsc_fractional_bpp_restore_fd = -1;
 static int count = 0;
 
 const struct {
@@ -125,6 +128,16 @@ static void force_dsc_ycbcr420_enable(data_t *data)
 	igt_assert_f(ret > 0, "forcing dsc ycbcr420 debugfs_write failed\n");
 }
 
+static void force_dsc_fractional_bpp_enable(data_t *data)
+{
+	int ret;
+
+	igt_debug("Forcing DSC Fractional BPP on %s\n", data->output->name);
+	ret = igt_force_dsc_fractional_bpp_enable(data->drm_fd,
+						  data->output->name);
+	igt_assert_f(ret > 0, "forcing dsc fractional bpp debugfs_write failed\n");
+}
+
 static void save_force_dsc_en(data_t *data)
 {
 	force_dsc_en_orig =
@@ -171,11 +184,34 @@ static void restore_force_dsc_ycbcr420_en(void)
 	force_dsc_ycbcr420_restore_fd = -1;
 }
 
+static void save_force_dsc_fractional_bpp_en(data_t *data)
+{
+	force_dsc_fractional_bpp_en_orig =
+		igt_is_force_dsc_fractional_bpp_enabled(data->drm_fd,
+							data->output->name);
+	force_dsc_fractional_bpp_restore_fd =
+		igt_get_dsc_fractional_bpp_debugfs_fd(data->drm_fd,
+						      data->output->name);
+	igt_assert(force_dsc_fractional_bpp_restore_fd >= 0);
+}
+
+static void restore_force_dsc_fractional_bpp_en(void)
+{
+	if (force_dsc_fractional_bpp_restore_fd < 0)
+		return;
+
+	igt_debug("Restoring DSC Fractional BPP enable\n");
+	igt_assert(write(force_dsc_fractional_bpp_restore_fd, force_dsc_fractional_bpp_en_orig ? "1" : "0", 1) == 1);
+
+	close(force_dsc_fractional_bpp_restore_fd);
+	force_dsc_fractional_bpp_restore_fd = -1;
+}
 
 static void kms_dsc_exit_handler(int sig)
 {
 	restore_force_dsc_en();
 	restore_force_dsc_ycbcr420_en();
+	restore_force_dsc_fractional_bpp_en();
 }
 
 static drmModeModeInfo *get_highres_mode(igt_output_t *output)
@@ -224,6 +260,34 @@ static bool check_dsc_on_connector(data_t *data)
 	return true;
 }
 
+static bool is_dsc_fractional_bpp_supported(int drmfd, char *connector_name)
+{
+	int bpp_prec;
+
+	bpp_prec = igt_get_dsc_fractional_bpp_supported(drmfd, connector_name);
+
+	if (bpp_prec == 1)
+		return false;
+
+	return true;
+}
+
+static bool check_dsc_fractional_bpp_on_connector(data_t *data)
+{
+	igt_output_t *output = data->output;
+
+	if (data->disp_ver >= 14) {
+		if (!is_dsc_fractional_bpp_supported(data->drm_fd, output->name)) {
+			igt_debug("DSC fractional bpp not supported on connector %s\n",
+				   output->name);
+			return false;
+		} else
+			return true;
+	}
+
+	return false;
+}
+
 static bool is_dsc_ycbcr420_supported(data_t *data)
 {
 	igt_output_t *output = data->output;
@@ -323,6 +387,10 @@ static void update_display(data_t *data, enum dsc_test_type test_type,
 		if (test_type == TEST_DSC_BPC) {
 			igt_debug("Trying to set input BPC to %d\n", data->input_bpc);
 			force_dsc_enable_bpc(data);
+		} else if (test_type == TEST_DSC_FRACTIONAL_BPP) {
+			igt_debug("DSC fractional bpp is supported on %s\n", data->output->name);
+			save_force_dsc_fractional_bpp_en(data);
+			force_dsc_fractional_bpp_enable(data);
 		}
 
 		igt_output_set_pipe(output, data->pipe);
@@ -371,11 +439,16 @@ static void update_display(data_t *data, enum dsc_test_type test_type,
 					enabled ? "ON" : "OFF");
 
 		restore_force_dsc_en();
+
 		if (output_format == DSC_FORMAT_YCBCR420)
 			restore_force_dsc_ycbcr420_en();
-		igt_debug("Reset compression BPC\n");
-		data->input_bpc = 0;
-		force_dsc_enable_bpc(data);
+
+		if (test_type == TEST_DSC_BPC) {
+			igt_debug("Reset compression BPC\n");
+			data->input_bpc = 0;
+			force_dsc_enable_bpc(data);
+		} else if (test_type == TEST_DSC_FRACTIONAL_BPP)
+			restore_force_dsc_fractional_bpp_en();
 
 		igt_assert_f(enabled,
 			    "Default DSC enable failed on connector: %s pipe: %s\n",
@@ -411,6 +484,9 @@ static void test_dsc(data_t *data, enum dsc_test_type test_type, int bpc,
 		if (!check_big_joiner_pipe_constraint(data))
 			continue;
 
+		if ((test_type == TEST_DSC_FRACTIONAL_BPP) && !(check_dsc_fractional_bpp_on_connector(data)))
+			continue;
+
 		if (test_type == TEST_DSC_BPC)
 			snprintf(name, sizeof(name), "-%dbpc-%s", data->input_bpc, igt_format_str(plane_format));
 		else
@@ -483,6 +559,13 @@ igt_main
 		}
 	}
 
+	igt_describe("Tests fractional compressed bpp functionality if supported "
+		     "by a connector by forcing fractional_bpp on all connectors that support it "
+		     "with default parameter. Driver will continue if output_bpp "
+		     "is computed as integer and allow DSC iff compressed bpp is fractional");
+	igt_subtest_with_dynamic("dsc-fractional-bpp")
+			run_test(&data, TEST_DSC_FRACTIONAL_BPP, 0, DRM_FORMAT_XRGB8888);
+
 	igt_fixture {
 		igt_display_fini(&data.display);
 		close(data.drm_fd);
-- 
2.25.1