[igt-dev] [PATCH i-g-t 2/3] 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.

v2: -change in igt_describe (Ankit)
v3: -rebase

Signed-off-by: Swati Sharma <swati2.sharma@intel.com>
Reviewed-by: Ankit Nautiyal <ankit.k.nautiyal@intel.com>
---
 tests/i915/kms_dsc.c        | 21 +++++++++++++
 tests/i915/kms_dsc_helper.c | 60 +++++++++++++++++++++++++++++++++++++
 tests/i915/kms_dsc_helper.h |  4 +++
 3 files changed, 85 insertions(+)

diff --git a/tests/i915/kms_dsc.c b/tests/i915/kms_dsc.c
index 3ce28f84..8aaec288 100644
--- a/tests/i915/kms_dsc.c
+++ b/tests/i915/kms_dsc.c
@@ -38,6 +38,7 @@ enum dsc_test_type {
 	TEST_DSC_BASIC,
 	TEST_DSC_BPC,
 	TEST_DSC_OUTPUT_FORMAT,
+	TEST_DSC_FRACTIONAL_BPP,
 };
 
 typedef struct {
@@ -139,6 +140,12 @@ static void update_display(data_t *data, enum dsc_test_type test_type)
 		force_dsc_output_format(data->drm_fd, data->output, data->output_format);
 	}
 
+	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->drm_fd, data->output);
+		force_dsc_fractional_bpp_enable(data->drm_fd, data->output);
+	}
+
 	igt_output_set_pipe(output, data->pipe);
 	primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
 
@@ -198,6 +205,7 @@ static void update_display(data_t *data, enum dsc_test_type test_type)
 				enabled ? "ON" : "OFF");
 
 	restore_force_dsc_en();
+	restore_force_dsc_fractional_bpp_en();
 
 	igt_assert_f(enabled,
 		     "Default DSC enable failed on connector: %s pipe: %s\n",
@@ -234,6 +242,10 @@ static void test_dsc(data_t *data, enum dsc_test_type test_type, int bpc,
 						    data->output, data->output_format))
 			continue;
 
+		if (!(check_dsc_fractional_bpp_on_connector(data->disp_ver,
+							    data->drm_fd, data->output)))
+			continue;
+
 		if (!check_gen11_dp_constraint(data->drm_fd, data->output, data->pipe))
 			continue;
 
@@ -314,6 +326,15 @@ igt_main
 				 output_format_list[k]);
 	}
 
+	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. While finding the optimum compressed bpp, driver will "
+		     "skip over the compressed bpps with integer values. It will go ahead with DSC, "
+		     "iff compressed bpp is fractional, failing in which, it will fail the commit.");
+	igt_subtest_with_dynamic("dsc-fractional-bpp")
+			test_dsc(&data, TEST_DSC_FRACTIONAL_BPP, 0, DRM_FORMAT_XRGB8888,
+				 DSC_FORMAT_RGB);
+
 	igt_fixture {
 		igt_display_fini(&data.display);
 		close(data.drm_fd);
diff --git a/tests/i915/kms_dsc_helper.c b/tests/i915/kms_dsc_helper.c
index 02d1a484..1f7b063e 100644
--- a/tests/i915/kms_dsc_helper.c
+++ b/tests/i915/kms_dsc_helper.c
@@ -6,7 +6,9 @@
 #include "kms_dsc_helper.h"
 
 static bool force_dsc_en_orig;
+static bool force_dsc_fractional_bpp_en_orig;
 static int force_dsc_restore_fd = -1;
+static int force_dsc_fractional_bpp_restore_fd = -1;
 
 void force_dsc_enable(int drmfd, igt_output_t *output)
 {
@@ -51,6 +53,7 @@ void restore_force_dsc_en(void)
 void kms_dsc_exit_handler(int sig)
 {
 	restore_force_dsc_en();
+	restore_force_dsc_fractional_bpp_en();
 }
 
 bool check_dsc_on_connector(int drmfd, igt_output_t *output)
@@ -133,3 +136,60 @@ bool is_dsc_output_format_supported(int drmfd, int disp_ver, igt_output_t *outpu
 
 	return true;
 }
+
+void force_dsc_fractional_bpp_enable(int drmfd, igt_output_t *output)
+{
+	int ret;
+
+	igt_debug("Forcing DSC Fractional BPP on %s\n", output->name);
+	ret = igt_force_dsc_fractional_bpp_enable(drmfd, output->name);
+	igt_assert_f(ret == 0, "forcing dsc fractional bpp debugfs_write failed\n");
+}
+
+void save_force_dsc_fractional_bpp_en(int drmfd, igt_output_t *output)
+{
+	force_dsc_fractional_bpp_en_orig =
+		igt_is_force_dsc_fractional_bpp_enabled(drmfd, output->name);
+	force_dsc_fractional_bpp_restore_fd =
+		igt_get_dsc_fractional_bpp_debugfs_fd(drmfd, output->name);
+	igt_assert(force_dsc_fractional_bpp_restore_fd >= 0);
+}
+
+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
+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;
+}
+
+bool check_dsc_fractional_bpp_on_connector(int disp_ver, int drmfd, igt_output_t *output)
+{
+	if (disp_ver >= 14) {
+		if (!is_dsc_fractional_bpp_supported(drmfd, output->name)) {
+			igt_debug("DSC fractional bpp not supported on connector %s\n",
+				   output->name);
+			return false;
+		} else
+			return true;
+	}
+
+	return false;
+}
diff --git a/tests/i915/kms_dsc_helper.h b/tests/i915/kms_dsc_helper.h
index 198f5afa..11db5a30 100644
--- a/tests/i915/kms_dsc_helper.h
+++ b/tests/i915/kms_dsc_helper.h
@@ -33,5 +33,9 @@ void force_dsc_output_format(int drmfd, igt_output_t *output,
 			     enum dsc_output_format output_format);
 bool is_dsc_output_format_supported(int disp_ver, int drmfd, igt_output_t *output,
 				    enum dsc_output_format output_format);
+void force_dsc_fractional_bpp_enable(int drmfd, igt_output_t *output);
+void save_force_dsc_fractional_bpp_en(int drmfd, igt_output_t *output);
+void restore_force_dsc_fractional_bpp_en(void);
+bool check_dsc_fractional_bpp_on_connector(int disp_ver, int drmfd, igt_output_t *output);
 
 #endif
-- 
2.25.1