Debugging LUT math is much easier when we can unit test
it. Add kunit functionality to VKMS and add tests for
- get_lut_index
- lerp_u16
Signed-off-by: Harry Wentland <harry.wentland@xxxxxxx>
Cc: Arthur Grillo <arthurgrillo@xxxxxxxxxx>
---
v6:
- Eliminate need to include test as .c file (Louis Chauvet)
v5:
- Bring back static for lerp_u16 and get_lut_index (Arthur)
v4:
- Test the critical points of the lerp function (Pekka)
v3:
- Use include way of testing static functions (Arthur)
drivers/gpu/drm/vkms/Kconfig | 15 ++
drivers/gpu/drm/vkms/Makefile | 1 +
drivers/gpu/drm/vkms/tests/.kunitconfig | 4 +
drivers/gpu/drm/vkms/tests/Makefile | 3 +
drivers/gpu/drm/vkms/tests/vkms_color_test.c | 168 +++++++++++++++++++
drivers/gpu/drm/vkms/vkms_composer.c | 10 +-
drivers/gpu/drm/vkms/vkms_composer.h | 13 ++
7 files changed, 211 insertions(+), 3 deletions(-)
create mode 100644 drivers/gpu/drm/vkms/tests/.kunitconfig
create mode 100644 drivers/gpu/drm/vkms/tests/Makefile
create mode 100644 drivers/gpu/drm/vkms/tests/vkms_color_test.c
create mode 100644 drivers/gpu/drm/vkms/vkms_composer.h
diff --git a/drivers/gpu/drm/vkms/Kconfig b/drivers/gpu/drm/vkms/Kconfig
index b9ecdebecb0b..59c4a32adb9d 100644
--- a/drivers/gpu/drm/vkms/Kconfig
+++ b/drivers/gpu/drm/vkms/Kconfig
@@ -13,3 +13,18 @@ config DRM_VKMS
a VKMS.
If M is selected the module will be called vkms.
+
+config DRM_VKMS_KUNIT_TESTS
+ tristate "KUnit tests for VKMS." if !KUNIT_ALL_TESTS
+ depends on DRM_VKMS=y && KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ This builds unit tests for VKMS. This option is not useful for
+ distributions or general kernels, but only for kernel
+ developers working on VKMS.
+
+ For more information on KUnit and unit tests in general,
+ please refer to the KUnit documentation in
+ Documentation/dev-tools/kunit/.
+
+ If in doubt, say "N".
diff --git a/drivers/gpu/drm/vkms/Makefile b/drivers/gpu/drm/vkms/Makefile
index 1b28a6a32948..8d3e46dde635 100644
--- a/drivers/gpu/drm/vkms/Makefile
+++ b/drivers/gpu/drm/vkms/Makefile
@@ -9,3 +9,4 @@ vkms-y := \
vkms_writeback.o
obj-$(CONFIG_DRM_VKMS) += vkms.o
+obj-$(CONFIG_DRM_VKMS_KUNIT_TESTS) += tests/
diff --git a/drivers/gpu/drm/vkms/tests/.kunitconfig b/drivers/gpu/drm/vkms/tests/.kunitconfig
new file mode 100644
index 000000000000..70e378228cbd
--- /dev/null
+++ b/drivers/gpu/drm/vkms/tests/.kunitconfig
@@ -0,0 +1,4 @@
+CONFIG_KUNIT=y
+CONFIG_DRM=y
+CONFIG_DRM_VKMS=y
+CONFIG_DRM_VKMS_KUNIT_TESTS=y
diff --git a/drivers/gpu/drm/vkms/tests/Makefile b/drivers/gpu/drm/vkms/tests/Makefile
new file mode 100644
index 000000000000..7876ca7a3c42
--- /dev/null
+++ b/drivers/gpu/drm/vkms/tests/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0-only
+
+obj-$(CONFIG_DRM_VKMS_KUNIT_TESTS) += vkms_color_test.o
\ No newline at end of file
diff --git a/drivers/gpu/drm/vkms/tests/vkms_color_test.c b/drivers/gpu/drm/vkms/tests/vkms_color_test.c
new file mode 100644
index 000000000000..efe139978860
--- /dev/null
+++ b/drivers/gpu/drm/vkms/tests/vkms_color_test.c
@@ -0,0 +1,168 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#include <kunit/test.h>
+
+#include <drm/drm_fixed.h>
+#include <drm/drm_mode.h>
+#include "../vkms_drv.h"
+#include "../vkms_composer.h"
+
+#define TEST_LUT_SIZE 16
+
+MODULE_IMPORT_NS(EXPORTED_FOR_KUNIT_TESTING);
+
+static struct drm_color_lut test_linear_array[TEST_LUT_SIZE] = {
+ { 0x0, 0x0, 0x0, 0 },
+ { 0x1111, 0x1111, 0x1111, 0 },
+ { 0x2222, 0x2222, 0x2222, 0 },
+ { 0x3333, 0x3333, 0x3333, 0 },
+ { 0x4444, 0x4444, 0x4444, 0 },
+ { 0x5555, 0x5555, 0x5555, 0 },
+ { 0x6666, 0x6666, 0x6666, 0 },
+ { 0x7777, 0x7777, 0x7777, 0 },
+ { 0x8888, 0x8888, 0x8888, 0 },
+ { 0x9999, 0x9999, 0x9999, 0 },
+ { 0xaaaa, 0xaaaa, 0xaaaa, 0 },
+ { 0xbbbb, 0xbbbb, 0xbbbb, 0 },
+ { 0xcccc, 0xcccc, 0xcccc, 0 },
+ { 0xdddd, 0xdddd, 0xdddd, 0 },
+ { 0xeeee, 0xeeee, 0xeeee, 0 },
+ { 0xffff, 0xffff, 0xffff, 0 },
+};
+
+const struct vkms_color_lut test_linear_lut = {
+ .base = test_linear_array,
+ .lut_length = TEST_LUT_SIZE,
+ .channel_value2index_ratio = 0xf000fll
+};
+
+
+static void vkms_color_test_get_lut_index(struct kunit *test)
+{
+ int i;
+
+ KUNIT_EXPECT_EQ(test, drm_fixp2int(get_lut_index(&test_linear_lut, test_linear_array[0].red)), 0);
+
+ for (i = 0; i < TEST_LUT_SIZE; i++)
+ KUNIT_EXPECT_EQ(test, drm_fixp2int_ceil(get_lut_index(&test_linear_lut, test_linear_array[i].red)), i);
+}
+
+static void vkms_color_test_lerp(struct kunit *test)
+{
+ /*** half-way round down ***/
+ s64 t = 0x80000000 - 1;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x8);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x8);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0x8);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x10);
+
+
+ /*** half-way round up ***/
+ t = 0x80000000;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x8);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x9);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0x8);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x11);
+
+ /*** t = 0.0 ***/
+ t = 0x0;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x0);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x1);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0x1);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x10);
+
+ /*** t = 1.0 ***/
+ t = 0x100000000;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x10);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x10);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0xf);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x11);
+
+
+ /*** t = 0.0 + 1 ***/
+ t = 0x0 + 1;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x0);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x1);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0x1);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x10);
+
+ /*** t = 1.0 - 1 ***/
+ t = 0x100000000 - 1;
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x10, t), 0x10);
+
+ /* odd a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0x10, t), 0x10);
+
+ /* odd b */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x1, 0xf, t), 0xf);
+
+ /* b = a */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x10, t), 0x10);
+
+ /* b = a + 1 */
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x10, 0x11, t), 0x11);
+
+
+ /*** t chosen to verify the flipping point of result a (or b) to a+1 (or b-1) ***/
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x1, 0x80000000 - 1), 0x0);
+ KUNIT_EXPECT_EQ(test, lerp_u16(0x0, 0x1, 0x80000000), 0x1);
+}
+
+static struct kunit_case vkms_color_test_cases[] = {
+ KUNIT_CASE(vkms_color_test_get_lut_index),
+ KUNIT_CASE(vkms_color_test_lerp),
+ {}
+};
+
+static struct kunit_suite vkms_color_test_suite = {
+ .name = "vkms-color",
+ .test_cases = vkms_color_test_cases,
+};
+kunit_test_suite(vkms_color_test_suite);
+
+MODULE_LICENSE("GPL");
\ No newline at end of file
diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c
index 3d6785d081f2..93f4ed5ea52f 100644
--- a/drivers/gpu/drm/vkms/vkms_composer.c
+++ b/drivers/gpu/drm/vkms/vkms_composer.c
@@ -12,6 +12,8 @@
#include <linux/minmax.h>
#include "vkms_drv.h"
+#include <kunit/visibility.h>
+#include "vkms_composer.h"
static u16 pre_mul_blend_channel(u16 src, u16 dst, u16 alpha)
{
@@ -91,7 +93,7 @@ static void fill_background(const struct pixel_argb_u16 *background_color,
}
// lerp(a, b, t) = a + (b - a) * t
-static u16 lerp_u16(u16 a, u16 b, s64 t)
+VISIBLE_IF_KUNIT u16 lerp_u16(u16 a, u16 b, s64 t)
{
s64 a_fp = drm_int2fixp(a);
s64 b_fp = drm_int2fixp(b);
@@ -100,13 +102,15 @@ static u16 lerp_u16(u16 a, u16 b, s64 t)
return drm_fixp2int_round(a_fp + delta);
}
+EXPORT_SYMBOL_IF_KUNIT(lerp_u16);
-static s64 get_lut_index(const struct vkms_color_lut *lut, u16 channel_value)
+VISIBLE_IF_KUNIT s64 get_lut_index(const struct vkms_color_lut *lut, u16 channel_value)
{
s64 color_channel_fp = drm_int2fixp(channel_value);
return drm_fixp_mul(color_channel_fp, lut->channel_value2index_ratio);
}
+EXPORT_SYMBOL_IF_KUNIT(get_lut_index);
/*
* This enum is related to the positions of the variables inside
@@ -434,4 +438,4 @@ int vkms_set_crc_source(struct drm_crtc *crtc, const char *src_name)
vkms_set_composer(out, enabled);
return ret;
-}
+}
\ No newline at end of file
diff --git a/drivers/gpu/drm/vkms/vkms_composer.h b/drivers/gpu/drm/vkms/vkms_composer.h
new file mode 100644
index 000000000000..9316a053e7d7
--- /dev/null
+++ b/drivers/gpu/drm/vkms/vkms_composer.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef _VKMS_COMPOSER_H_
+#define _VKMS_COMPOSER_H_
+
+#include <kunit/visibility.h>
+
+#if IS_ENABLED(CONFIG_KUNIT)
+u16 lerp_u16(u16 a, u16 b, s64 t);
+s64 get_lut_index(const struct vkms_color_lut *lut, u16 channel_value);
+#endif
+
+#endif /* _VKMS_COMPOSER_H_ */
--
2.46.2
