Hi, On Mon, Sep 08, 2025 at 11:00:30AM +0200, Jocelyn Falempe wrote: > Add kunit tests for drm_panic. > They check that drawing the panic screen doesn't crash, but they > don't check the correctness of the resulting image. > > Signed-off-by: Jocelyn Falempe <jfale...@redhat.com> > --- > > v2: > * Add a few checks, and more comments in the kunit tests. (Maxime Ripard). > > MAINTAINERS | 1 + > drivers/gpu/drm/drm_panic.c | 4 + > drivers/gpu/drm/tests/drm_panic_test.c | 198 +++++++++++++++++++++++++ > 3 files changed, 203 insertions(+) > create mode 100644 drivers/gpu/drm/tests/drm_panic_test.c > > diff --git a/MAINTAINERS b/MAINTAINERS > index 402fe14091f1..e9be893d6741 100644 > --- a/MAINTAINERS > +++ b/MAINTAINERS > @@ -8480,6 +8480,7 @@ T: git > https://gitlab.freedesktop.org/drm/misc/kernel.git > F: drivers/gpu/drm/drm_draw.c > F: drivers/gpu/drm/drm_draw_internal.h > F: drivers/gpu/drm/drm_panic*.c > +F: drivers/gpu/drm/tests/drm_panic_test.c > F: include/drm/drm_panic* > > DRM PANIC QR CODE > diff --git a/drivers/gpu/drm/drm_panic.c b/drivers/gpu/drm/drm_panic.c > index 1e06e3a18d09..d89812ff1935 100644 > --- a/drivers/gpu/drm/drm_panic.c > +++ b/drivers/gpu/drm/drm_panic.c > @@ -986,3 +986,7 @@ void drm_panic_exit(void) > { > drm_panic_qr_exit(); > } > + > +#ifdef CONFIG_DRM_KUNIT_TEST > +#include "tests/drm_panic_test.c" > +#endif > diff --git a/drivers/gpu/drm/tests/drm_panic_test.c > b/drivers/gpu/drm/tests/drm_panic_test.c > new file mode 100644 > index 000000000000..d5d20dd2aa7c > --- /dev/null > +++ b/drivers/gpu/drm/tests/drm_panic_test.c > @@ -0,0 +1,198 @@ > +// SPDX-License-Identifier: GPL-2.0 or MIT > +/* > + * Copyright (c) 2025 Red Hat. > + * Author: Jocelyn Falempe <jfale...@redhat.com> > + * > + * KUNIT tests for drm panic > + */ > + > +#include <drm/drm_fourcc.h> > +#include <drm/drm_panic.h> > + > +#include <kunit/test.h> > + > +#include <linux/units.h> > +#include <linux/vmalloc.h> > + > +/* Check the framebuffer color only if the panic colors are the default */ > +#if (CONFIG_DRM_PANIC_BACKGROUND_COLOR == 0 && \ > + CONFIG_DRM_PANIC_FOREGROUND_COLOR == 0xffffff) > +#define DRM_PANIC_CHECK_COLOR > +#endif > + > +struct drm_test_mode { > + const int width; > + const int height; > + const u32 format; > + void (*draw_screen)(struct drm_scanout_buffer *sb); > + const char *fname; > +}; > + > +/* > + * Run all tests for the 3 panic screens: user, kmsg and qr_code > + */ > +#define DRM_TEST_MODE_LIST(func) \ > + DRM_PANIC_TEST_MODE(1024, 768, DRM_FORMAT_XRGB8888, func) \ > + DRM_PANIC_TEST_MODE(300, 200, DRM_FORMAT_XRGB8888, func) \ > + DRM_PANIC_TEST_MODE(1920, 1080, DRM_FORMAT_XRGB8888, func) \ > + DRM_PANIC_TEST_MODE(1024, 768, DRM_FORMAT_RGB565, func) \ > + DRM_PANIC_TEST_MODE(1024, 768, DRM_FORMAT_RGB888, func) \ > + > +#define DRM_PANIC_TEST_MODE(w, h, f, name) { \ > + .width = w, \ > + .height = h, \ > + .format = f, \ > + .draw_screen = draw_panic_screen_##name, \ > + .fname = #name, \ > + }, \ > + > +static const struct drm_test_mode drm_test_modes_cases[] = { > + DRM_TEST_MODE_LIST(user) > + DRM_TEST_MODE_LIST(kmsg) > + DRM_TEST_MODE_LIST(qr_code) > +}; > +#undef DRM_PANIC_TEST_MODE > + > +static int drm_test_panic_init(struct kunit *test) > +{ > + struct drm_scanout_buffer *priv; > + > + priv = kunit_kzalloc(test, sizeof(*priv), GFP_KERNEL); > + KUNIT_ASSERT_NOT_NULL(test, priv); > + > + test->priv = priv; > + > + drm_panic_set_description("Kunit testing"); > + > + return 0; > +} > + > +/* > + * Test drawing the panic screen, using a memory mapped framebuffer > + * Set the whole buffer to 0xa5, and then check that all pixels have been > + * written. > + */ > +static void drm_test_panic_screen_user_map(struct kunit *test) > +{ > + struct drm_scanout_buffer *sb = test->priv; > + const struct drm_test_mode *params = test->param_value; > + char *fb; > + int fb_size; > + > + sb->format = drm_format_info(params->format); > + fb_size = params->width * params->height * sb->format->cpp[0]; > + > + fb = vmalloc(fb_size); > + KUNIT_ASSERT_NOT_NULL(test, fb); > + > + memset(fb, 0xa5, fb_size); > + > + iosys_map_set_vaddr(&sb->map[0], fb); > + sb->width = params->width; > + sb->height = params->height; > + sb->pitch[0] = params->width * sb->format->cpp[0]; > + > + params->draw_screen(sb); > + > +#ifdef DRM_PANIC_CHECK_COLOR > + { > + int i; > + > + for (i = 0; i < fb_size; i++) > + KUNIT_ASSERT_TRUE(test, fb[i] == 0 || fb[i] == 0xff); > + } > +#endif
I'm not really fond of the ifdef here. Could you turn this into a
function, and return that it's valid if the colors don't match what you
expect?
> + vfree(fb);
> +}
> +
> +/*
> + * Test drawing the panic screen, using a list of pages framebuffer
> + * No checks are performed
What are you testing then if you aren't checking anything?
> + */
> +static void drm_test_panic_screen_user_page(struct kunit *test)
> +{
> + struct drm_scanout_buffer *sb = test->priv;
> + const struct drm_test_mode *params = test->param_value;
> + int fb_size;
> + struct page **pages;
> + int i;
> + int npages;
> +
> + sb->format = drm_format_info(params->format);
> + fb_size = params->width * params->height * sb->format->cpp[0];
> + npages = DIV_ROUND_UP(fb_size, PAGE_SIZE);
> +
> + pages = kmalloc_array(npages, sizeof(struct page *), GFP_KERNEL);
> + KUNIT_ASSERT_NOT_NULL(test, pages);
> +
> + for (i = 0; i < npages; i++) {
> + pages[i] = alloc_page(GFP_KERNEL);
> + KUNIT_ASSERT_NOT_NULL(test, pages[i]);
KUNIT_ASSERT_* return immediately, so you're leaking the pages array
here.
Maxime
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