From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 428E3C54E67 for ; Fri, 15 Mar 2024 16:11:33 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id EC955112334; Fri, 15 Mar 2024 16:11:32 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.b="b99sGeRq"; dkim-atps=neutral Received: from relay4-d.mail.gandi.net (relay4-d.mail.gandi.net [217.70.183.196]) by gabe.freedesktop.org (Postfix) with ESMTPS id 9CA41112334 for ; Fri, 15 Mar 2024 16:11:31 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id BECD2E0006; Fri, 15 Mar 2024 16:11:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1710519089; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=HE83UH6tNBoC83guSGArN7GC62hKYTsn2VktGoHgA4o=; b=b99sGeRqNOo6KBFRomSvLhgWu2Gzp2n6jJUhmdolec4dWS8kSj1L/EO1ImDEE0FYAftjI9 OSOmRSNKf1ZW/afXKF7w/hdcAw6ZgDhgnipJY9ICoU1O7MBieKo9lOyBb7tNVdg5n2DCHi 2A7c39iZtn4EzzhRYDKpK7rvlZJR6M6K8+sQdS0f599wh1T1dqL8X0LtyOKUZxamIXdnUv 9TOcbrw0Xyrj0jRcKJfE+kSd9UcopzSl6VpJ7DKxslq2P6AkDcwbE0NkdZFF3sfW2cGiuR 51gTweIX8Fp2xtuSr23ZTgcNIfxdHqmYeh8/nAoQllIaTLP0Mop8sHKZo8S9nw== Date: Fri, 15 Mar 2024 17:11:27 +0100 From: Louis Chauvet To: Kamil Konieczny , igt-dev@lists.freedesktop.org, miquel.raynal@bootlin.com, jeremie.dautheribes@bootlin.com, thomas.petazzoni@bootlin.com, arthurgrillo@riseup.net, Mauro Carvalho Chehab Subject: Re: [PATCH i-g-t v2 3/4] tests/kms_rotation: Add extensive rotation test Message-ID: References: <20240313-new_rotation-v2-0-6230fd5cae59@bootlin.com> <20240313-new_rotation-v2-3-6230fd5cae59@bootlin.com> <20240314170643.77vzqqoie2otyu4w@kamilkon-desk.igk.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20240314170643.77vzqqoie2otyu4w@kamilkon-desk.igk.intel.com> X-GND-Sasl: louis.chauvet@bootlin.com X-BeenThere: igt-dev@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development mailing list for IGT GPU Tools List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: igt-dev-bounces@lists.freedesktop.org Sender: "igt-dev" Le 14/03/24 - 18:06, Kamil Konieczny a écrit : > Hi Louis, > On 2024-03-13 at 18:09:42 +0100, Louis Chauvet wrote: > > The actual kms_rotation_crc test does not tes all the rotation with all > > the formats. Create the test kms_rotation, which only test "full plane > > rotation", but for all formats, planes and rotations. > > > > This allow the detection of issues like in [1], where the YUV rotation is > > not working for specific rotations. > > > > [1]: https://lore.kernel.org/dri-devel/20240304-yuv-v4-11-76beac8e9793@bootlin.com/ > > > > Signed-off-by: Louis Chauvet > > --- > > tests/kms_rotation.c | 444 +++++++++++++++++++++++++++++++++++++++++++++++++++ > > tests/meson.build | 1 + > > 2 files changed, 445 insertions(+) > > > > diff --git a/tests/kms_rotation.c b/tests/kms_rotation.c > > new file mode 100644 > > index 000000000000..333485619541 > > --- /dev/null > > +++ b/tests/kms_rotation.c > > @@ -0,0 +1,444 @@ Hi Kamil, > Please add here SPDX MIT licence. I did not know that was needed, I will add it for the v3. (Same for the nit in meson.build, I will send a v3 in aphabetical order) > > +#include "igt.h" > > + > > +/** > > + * TEST: kms_rotation > > + * Category: Display > > + * Description: Tests all rotations for all planes and formats. > > + * Driver requirement: none > ------------------------- ^ > It is better to not have 'none' as a driver, just drop this line. I will remove it for the v3. > +cc Mauro. > > Please use checkpatch.pl script from Linux kernel, > it can spot some code style problems (line too long can > be sometimes ignored). Sorry for that, it was not explained in CONTRIBUTING.md. I created a series [1] to add it in the CONTRIBUTING.md file. Kind regards, Louis Chauvet [1]: https://lore.kernel.org/all/20240315-add_coding_style-v1-1-50ad93cfa250@bootlin.com/ > Regards, > Kamil > > > + * Functionality: plane, rotation > > + * Mega feature: General Display Features > > + * Test category: functionality test > > + */ > > + > > +/** > > + * SUBTEST: rotations > > + * Description: Test for all rotations, planes and formats. > > + */ > > + > > +/** > > + * struct data_t - Stores the test configuration > > + * > > + * @fd: file descriptor for the current drm device > > + * @display: display used for the tests > > + * @width, @height: Size of the CRTC used for this test > > + */ > > +struct data_t { > > + int fd; > > + igt_display_t display; > > + uint32_t width; > > + uint32_t height; > > +}; > > + > > +/** > > + * colors - List of colors used to put things on the plane > > + * > > + * Those colors are used to create a color pattern on the plane, which is not invariant by rotation or reflexion. > > + * > > + * At least black and white must be in this list to properly test black and white formats. > > + */ > > +static const struct igt_vec4 colors[] = { > > + {{1.0f, 0.0f, 0.0f, 0.0f}}, > > + {{1.0f, 1.0f, 1.0f, 0.0f}}, > > + {{0.0f, 0.0f, 0.0f, 0.0f}}, > > + {{0.0f, 1.0f, 1.0f, 0.0f}}, > > + {{0.0f, 0.0f, 0.0f, 0.0f}}, > > +}; > > + > > +/** > > + * tested_rotation - List of all tested rotation configuration > > + */ > > +static uint32_t tested_rotation[] = { > > + IGT_ROTATION_0, > > + IGT_ROTATION_0 | IGT_REFLECT_X, > > + IGT_ROTATION_0 | IGT_REFLECT_Y, > > + IGT_ROTATION_0 | IGT_REFLECT_X | IGT_REFLECT_Y, > > + IGT_ROTATION_90, > > + IGT_ROTATION_90 | IGT_REFLECT_X, > > + IGT_ROTATION_90 | IGT_REFLECT_Y, > > + IGT_ROTATION_90 | IGT_REFLECT_X | IGT_REFLECT_Y, > > + IGT_ROTATION_180, > > + IGT_ROTATION_180 | IGT_REFLECT_X, > > + IGT_ROTATION_180 | IGT_REFLECT_Y, > > + IGT_ROTATION_180 | IGT_REFLECT_X | IGT_REFLECT_Y, > > + IGT_ROTATION_270, > > + IGT_ROTATION_270 | IGT_REFLECT_X, > > + IGT_ROTATION_270 | IGT_REFLECT_Y, > > + IGT_ROTATION_270 | IGT_REFLECT_X | IGT_REFLECT_Y, > > +}; > > + > > +/** > > + * non_equals_crc() - Check if at least one CRC is different > > + * > > + * Check if at least one CRC is different, so we can verify that the rendering is working. > > + * > > + * @crcs: List of all tested crcs > > + * @crc_count: Number of crcs in the list > > + */ > > +static bool non_equals_crc(igt_crc_t crcs[], int crc_count) > > +{ > > + if (!crc_count) { > > + return true; > > + } > > + for (int i = 0; i < crc_count; i++) > > + if (!igt_check_crc_equal(&crcs[i], &crcs[0])) > > + return true; > > + return false; > > +} > > + > > +/** > > + * create_fb() - Create a framebuffer > > + * > > + * This create a framebuffer and fill it with a pattern. This pattern is not invariant by rotation and reflection. > > + * > > + * The @width and @height parameters are automaticaly inverted according to @rotation if needed. If the requested plane > > + * is 1024*768 with IGT_ROTATION_90, the returned plane will have the size 768*1024. > > + * > > + * @data: Current test configuration > > + * @rotation: Rotation to apply to the pattern > > + * @format: Format of the requested plane > > + * @modifier: Modifier for the requested plane > > + * @width, @height: Size of the plane to use (without rotation) > > + * @width: Width of the requested plane > > + * @height: Height of the requested plane > > + * @fb: Place to store the created framebuffer > > + */ > > +static void create_fb(struct data_t *data, igt_rotation_t rotation, uint32_t format, uint64_t modifier, int width, > > + int height, igt_fb_t *fb) > > +{ > > + int step_x, step_y, color_index, current_n, current_m; > > + int offset_x, offset_y; > > + cairo_t *cr; > > + > > + switch (rotation & IGT_ROTATION_MASK) { > > + case IGT_ROTATION_90: > > + case IGT_ROTATION_270: > > + igt_swap(width, height); > > + break; > > + case IGT_ROTATION_0: > > + case IGT_ROTATION_180: > > + default: > > + break; > > + } > > + > > + igt_create_fb(data->fd, width, height, format, modifier, fb); > > + cr = igt_get_cairo_ctx(data->fd, fb); > > + > > + step_x = (width) / ARRAY_SIZE(colors); > > + step_y = (height) / ARRAY_SIZE(colors); > > + > > + /* > > + * This pair of offset is used to ensure that a software rotated plane is the same as a hardware rotated plane. > > + */ > > + switch ((int)rotation) { > > + case IGT_ROTATION_0: > > + case IGT_ROTATION_0 | IGT_REFLECT_Y: > > + case IGT_ROTATION_90: > > + case IGT_ROTATION_90 | IGT_REFLECT_X: > > + case IGT_ROTATION_180 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_180 | IGT_REFLECT_X: > > + case IGT_ROTATION_270 | IGT_REFLECT_Y: > > + case IGT_ROTATION_270 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + offset_x = 0; > > + break; > > + case IGT_ROTATION_0 | IGT_REFLECT_X: > > + case IGT_ROTATION_0 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_90 | IGT_REFLECT_Y: > > + case IGT_ROTATION_90 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_180: > > + case IGT_ROTATION_180 | IGT_REFLECT_Y: > > + case IGT_ROTATION_270: > > + case IGT_ROTATION_270 | IGT_REFLECT_X: > > + offset_x = width % step_x; > > + break; > > + } > > + switch ((int)rotation) { > > + case IGT_ROTATION_0: > > + case IGT_ROTATION_0 | IGT_REFLECT_X: > > + case IGT_ROTATION_90 | IGT_REFLECT_X: > > + case IGT_ROTATION_90 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_180 | IGT_REFLECT_Y: > > + case IGT_ROTATION_180 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_270: > > + case IGT_ROTATION_270 | IGT_REFLECT_Y: > > + offset_y = 0; > > + break; > > + case IGT_ROTATION_0 | IGT_REFLECT_Y: > > + case IGT_ROTATION_0 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + case IGT_ROTATION_90: > > + case IGT_ROTATION_90 | IGT_REFLECT_Y: > > + case IGT_ROTATION_180: > > + case IGT_ROTATION_180 | IGT_REFLECT_X: > > + case IGT_ROTATION_270 | IGT_REFLECT_X: > > + case IGT_ROTATION_270 | IGT_REFLECT_X | IGT_REFLECT_Y: > > + offset_y = height % step_y; > > + break; > > + } > > + > > + /* Iterate over all colors in x and y direction. The pattern is a colored chessboard */ > > + for (int n = 0; n < ARRAY_SIZE(colors); n++) { > > + for (int m = 0; m < ARRAY_SIZE(colors); m++) { > > + color_index = (n + m) % ARRAY_SIZE(colors); > > + current_n = n; > > + current_m = m; > > + > > + /* > > + * If a reflexion and a rotation is requested, apply this to the pattern rendering > > + * If a reflexion is given, it must be applied before the rotation. > > + */ > > + switch (rotation & IGT_REFLECT_MASK) { > > + case IGT_REFLECT_X: > > + current_n = ARRAY_SIZE(colors) - 1 - current_n; > > + break; > > + case IGT_REFLECT_Y: > > + current_m = ARRAY_SIZE(colors) - 1 - current_m; > > + break; > > + case IGT_REFLECT_X | IGT_REFLECT_Y: > > + current_n = ARRAY_SIZE(colors) - 1 - current_n; > > + current_m = ARRAY_SIZE(colors) - 1 - current_m; > > + break; > > + } > > + switch (rotation & IGT_ROTATION_MASK) { > > + case IGT_ROTATION_0: > > + break; > > + case IGT_ROTATION_90: > > + igt_swap(current_n, current_m); > > + current_m = ARRAY_SIZE(colors) - 1 - current_m; > > + break; > > + case IGT_ROTATION_180: > > + current_n = ARRAY_SIZE(colors) - 1 - current_n; > > + current_m = ARRAY_SIZE(colors) - 1 - current_m; > > + break; > > + case IGT_ROTATION_270: > > + igt_swap(current_n, current_m); > > + current_n = ARRAY_SIZE(colors) - 1 - current_n; > > + break; > > + } > > + > > + igt_paint_color(cr, > > + offset_x + current_n * step_x, > > + offset_y + current_m * step_y, > > + step_x, > > + step_y, > > + colors[color_index].d[0], > > + colors[color_index].d[1], > > + colors[color_index].d[2]); > > + } > > + } > > + > > + igt_put_cairo_ctx(cr); > > +} > > + > > +/** > > + * get_ref_crcs() - Compute the reference CRC for a specific format > > + * > > + * The rotation are done by create_fb in software. > > + * > > + * @data: Test configuration > > + * @output, @pipe, @plane: Plane to use for the test > > + * @width, @height: Size of the plane to use (without rotation) > > + * @format, @modifier: Format description to test > > + * @ref_crc: Array to store the resulting CRC. Its size must be at least ARRAY_SIZE(tested_rotation). > > + */ > > +static void get_ref_crcs(struct data_t *data, igt_output_t *output, enum pipe pipe, igt_plane_t *plane, int width, > > + int height, uint32_t format, uint64_t modifier, igt_crc_t ref_crc[ARRAY_SIZE(tested_rotation)]) > > +{ > > + drmModeModeInfo *mode; > > + igt_pipe_crc_t *pipe_crc; > > + igt_fb_t fb; > > + > > + igt_display_reset(&data->display); > > + igt_output_set_pipe(output, pipe); > > + > > + > > + for (int r = 0; r < ARRAY_SIZE(tested_rotation); r++) { > > + int rotation = tested_rotation[r]; > > + igt_debug("Computing reference CRC for rotation-%s-reflect-%s\n", igt_plane_rotation_name(rotation), > > + igt_plane_reflect_name(rotation)); > > + /* Configure the pipe for reference frame */ > > + igt_display_reset(&data->display); > > + > > + mode = igt_output_get_mode(output); > > + mode->hdisplay = width; > > + mode->vdisplay = height; > > + igt_output_override_mode(output, mode); > > + mode = igt_output_get_mode(output); > > + > > + igt_output_set_pipe(output, pipe); > > + igt_plane_set_rotation(plane, IGT_ROTATION_0); > > + igt_display_commit2(&data->display, COMMIT_ATOMIC); > > + > > + /* Start the CRC */ > > + pipe_crc = igt_pipe_crc_new(data->fd, pipe, IGT_PIPE_CRC_SOURCE_AUTO); > > + igt_pipe_crc_start(pipe_crc); > > + > > + create_fb(data, rotation, format, modifier, mode->vdisplay, mode->hdisplay, &fb); > > + igt_plane_set_fb(plane, &fb); > > + igt_display_commit2(&data->display, COMMIT_ATOMIC); > > + > > + igt_pipe_crc_get_current( > > + data->display.drm_fd, pipe_crc, > > + &ref_crc[r]); > > + > > + igt_pipe_crc_stop(pipe_crc); > > + igt_pipe_crc_free(pipe_crc); > > + igt_remove_fb(data->fd, &fb); > > + } > > +} > > + > > +/** > > + * get_crcs() - Compute the CRC for a specific format > > + * > > + * @data: Test configuration > > + * @output, @pipe, @plane: Plane to use for the test > > + * @width, @height: Size of the plane to use (without rotation) > > + * @format, @modifier: Format description to test > > + * @crc: Array to store the resulting CRC. Its size must be at least ARRAY_SIZE(tested_rotation). > > + */ > > +static void get_crcs(struct data_t *data, igt_output_t *output, enum pipe pipe, igt_plane_t *plane, int width, > > + int height, uint32_t format, uint64_t modifier, igt_crc_t crc[ARRAY_SIZE(tested_rotation)]) > > +{ > > + drmModeModeInfo *mode; > > + igt_pipe_crc_t *pipe_crc; > > + igt_fb_t fb; > > + > > + igt_display_reset(&data->display); > > + igt_output_set_pipe(output, pipe); > > + > > + for (int r = 0; r < ARRAY_SIZE(tested_rotation); r++) { > > + int rotation = tested_rotation[r]; > > + igt_debug("Computing CRC for rotation-%s-reflect-%s\n", igt_plane_rotation_name(rotation), > > + igt_plane_reflect_name(rotation)); > > + /* Configure the pipe for reference frame */ > > + igt_display_reset(&data->display); > > + > > + mode = igt_output_get_mode(output); > > + mode->hdisplay = width; > > + mode->vdisplay = height; > > + igt_output_override_mode(output, mode); > > + mode = igt_output_get_mode(output); > > + > > + igt_output_set_pipe(output, pipe); > > + igt_plane_set_rotation(plane, rotation); > > + > > + if (!igt_plane_has_rotation(plane, rotation)) > > + continue; > > + > > + igt_display_commit2(&data->display, COMMIT_ATOMIC); > > + > > + /* Start the CRC */ > > + pipe_crc = igt_pipe_crc_new(data->fd, pipe, IGT_PIPE_CRC_SOURCE_AUTO); > > + igt_pipe_crc_start(pipe_crc); > > + > > + create_fb(data, IGT_ROTATION_0, format, modifier, mode->vdisplay, mode->hdisplay, &fb); > > + igt_plane_set_fb(plane, &fb); > > + if (igt_rotation_90_or_270(rotation)) > > + igt_plane_set_size(plane, fb.height, fb.width); > > + igt_display_commit2(&data->display, COMMIT_ATOMIC); > > + > > + igt_pipe_crc_get_current( > > + data->display.drm_fd, pipe_crc, > > + &crc[r]); > > + > > + igt_pipe_crc_stop(pipe_crc); > > + igt_pipe_crc_free(pipe_crc); > > + igt_remove_fb(data->fd, &fb); > > + } > > +} > > + > > +/** > > + * run_test() - Run the subtests for a specific plane > > + * > > + * @data: Test configuration > > + * @output, @pipe, @plane: Plane to use for the test > > + * @format, @modifier: Format description to test > > + */ > > +static void run_test(struct data_t *data, igt_output_t *output, enum pipe pipe, igt_plane_t *plane, uint32_t format, > > + uint64_t modifier) > > +{ > > + int width, height; > > + const struct format_desc_struct *format_description; > > + igt_crc_t ref_crc[ARRAY_SIZE(tested_rotation)]; > > + igt_crc_t crc[ARRAY_SIZE(tested_rotation)]; > > + > > + igt_display_reset(&data->display); > > + igt_output_set_pipe(output, pipe); > > + /* Check that the rotation is supported */ > > + igt_require(igt_plane_has_prop(plane, IGT_PLANE_ROTATION)); > > + format_description = lookup_drm_format(format); > > + width = ARRAY_SIZE(colors) * format_description->hsub * format_description->vsub * 6; > > + height = ARRAY_SIZE(colors) * format_description->hsub * format_description->vsub * 6; > > + > > + /* Generate reference CRC with software rotation */ > > + get_ref_crcs(data, output, pipe, plane, width, height, format, modifier, ref_crc); > > + igt_assert_f(non_equals_crc(ref_crc, ARRAY_SIZE(tested_rotation)), "All the reference CRC are equals."); > > + > > + /* Generate CRC with hardware rotation */ > > + get_crcs(data, output, pipe, plane, width, height, format, modifier, crc); > > + > > + for (int c = 0; c < ARRAY_SIZE(tested_rotation); c++) { > > + int rotation = tested_rotation[c]; > > + igt_dynamic_f("pipe-%s-format-%s-modifier-%s-rotation-%s-reflect-%s", kmstest_pipe_name(pipe), > > + igt_format_str(format), > > + igt_fb_modifier_name(modifier), igt_plane_rotation_name(rotation), > > + igt_plane_reflect_name(rotation)) { > > + igt_assert_crc_equal(&ref_crc[c], &crc[c]); > > + } > > + } > > +} > > + > > +/** > > + * test_all_formats() - Run all the tests for all planes > > + * > > + * @data: Test configuration > > + */ > > +static void test_all_formats(struct data_t *data) > > +{ > > + enum pipe pipe; > > + struct igt_plane *plane; > > + igt_output_t *output; > > + for_each_pipe_with_single_output(&data->display, pipe, output) { > > + for_each_plane_on_pipe(&data->display, pipe, plane) { > > + for (int f = 0; f < plane->format_mod_count; f++) { > > + uint32_t format = plane->formats[f]; > > + uint32_t modifier = plane->modifiers[f]; > > + > > + if (!igt_fb_supported_format(format)) > > + continue; > > + run_test(data, output, pipe, plane, format, modifier); > > + } > > + } > > + } > > +} > > + > > +static int opt_handler(int opt, int opt_index, void *void_data) > > +{ > > + return IGT_OPT_HANDLER_SUCCESS; > > +} > > + > > +static const struct option long_opts[] = { > > + {} > > +}; > > + > > +static const char help_str[] = ""; > > + > > +static struct data_t global_data; > > + > > +igt_main_args("", long_opts, help_str, opt_handler, &global_data) > > +{ > > + igt_fixture { > > + global_data.fd = drm_open_driver_master(DRIVER_ANY); > > + > > + kmstest_set_vt_graphics_mode(); > > + > > + igt_display_require(&global_data.display, global_data.fd); > > + igt_require(global_data.display.is_atomic); > > + igt_display_require_output(&global_data.display); > > + igt_display_reset(&global_data.display); > > + } > > + > > + igt_describe("Testing different rotation and reflexions for different formats"); > > + igt_subtest_with_dynamic_f("rotations") { > > + test_all_formats(&global_data); > > + } > > + > > +} > > \ No newline at end of file > > diff --git a/tests/meson.build b/tests/meson.build > > index a856510fcea7..71b628b86e96 100644 > > --- a/tests/meson.build > > +++ b/tests/meson.build > > @@ -82,6 +82,7 @@ test_progs = [ > > 'tools_test', > > 'vgem_basic', > > 'vgem_slow', > > + 'kms_rotation', > > ] > > > > intel_i915_xe_progs = [ > > > > -- > > 2.43.0 > > -- Louis Chauvet, Bootlin Embedded Linux and Kernel engineering https://bootlin.com