On 29/01/25 - 12:00, José Expósito wrote: > Add a list of planes to vkms_config and create as many planes as > configured during output initialization. > > For backwards compatibility, add one primary plane and, if configured, > one cursor plane and NUM_OVERLAY_PLANES planes to the default > configuration. > > Signed-off-by: Louis Chauvet <[email protected]> > Signed-off-by: José Expósito <[email protected]>
Co-developped-by: Louis Chauvet <[email protected]> Signed-off-by: Louis Chauvet <[email protected]> Signed-off-by: José Expósito <[email protected]> [...] > diff --git a/drivers/gpu/drm/vkms/tests/vkms_config_test.c > b/drivers/gpu/drm/vkms/tests/vkms_config_test.c [...] > +static void vkms_config_test_get_planes(struct kunit *test) > +{ > + struct vkms_config *config; > + struct vkms_config_plane *plane_cfg1, *plane_cfg2; > + struct vkms_config_plane **array; > + size_t length; > + > + config = vkms_config_create("test"); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config); > + > + array = vkms_config_get_planes(config, &length); > + KUNIT_ASSERT_EQ(test, length, 0); > + KUNIT_ASSERT_NULL(test, array); > + > + plane_cfg1 = vkms_config_add_plane(config); > + array = vkms_config_get_planes(config, &length); > + KUNIT_ASSERT_EQ(test, length, 1); > + KUNIT_ASSERT_PTR_EQ(test, array[0], plane_cfg1); > + kfree(array); > + > + plane_cfg2 = vkms_config_add_plane(config); > + array = vkms_config_get_planes(config, &length); > + KUNIT_ASSERT_EQ(test, length, 2); > + KUNIT_ASSERT_PTR_EQ(test, array[0], plane_cfg1); > + KUNIT_ASSERT_PTR_EQ(test, array[1], plane_cfg2); > + kfree(array); > + > + vkms_config_destroy_plane(plane_cfg1); > + array = vkms_config_get_planes(config, &length); > + KUNIT_ASSERT_EQ(test, length, 1); > + KUNIT_ASSERT_PTR_EQ(test, array[0], plane_cfg2); > + kfree(array); > + > + vkms_config_destroy(config); > +} In this test I have the feeling that vkms_config_get_planes always returns a predictable order. It is maybe trivial here, but I would prefer to shows that the order is not stable, for example: bool plane_cfg1_found = false; bool plane_cfg2_found = false; vkms_config_for_each_plane(config, plane_cfg) { if (plane_cfg == plane_cfg1) plane_cfg1_found = true; else if (plane_cfg == plane_cfg2) plane_cfg2_found = true; else KUNIT_FAILS("Unexpected plane"); } KUNIT_ASSERT(test, plane_cfg1_found); KUNIT_ASSERT(test, plane_cfg2_found); [...] > +static void vkms_config_test_valid_plane_number(struct kunit *test) > +{ > + struct vkms_config *config; > + struct vkms_config_plane *plane_cfg; > + int n; > + > + config = vkms_config_default_create(false, false, false); > + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, config); > + > + /* Invalid: No planes */ > + plane_cfg = list_first_entry(&config->planes, typeof(*plane_cfg), link); > + vkms_config_destroy_plane(plane_cfg); > + KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config)); > + > + /* Invalid: Too many planes */ > + for (n = 0; n <= 32; n++) > + vkms_config_add_plane(config); > + > + KUNIT_EXPECT_FALSE(test, vkms_config_is_valid(config)); > + > + vkms_config_destroy(config); > +} For this function, the naming is a bit strange, it says "valid_plane_number", but you test only invalid plane number. Can you rename it to vkms_config_test_invalid_plane_number? [...] > diff --git a/drivers/gpu/drm/vkms/vkms_config.c > b/drivers/gpu/drm/vkms/vkms_config.c [...] > +struct vkms_config_plane **vkms_config_get_planes(const struct vkms_config > *config, > + size_t *out_length) > +{ > + struct vkms_config_plane **array; > + struct vkms_config_plane *plane_cfg; > + size_t length; > + int n = 0; > + > + length = list_count_nodes((struct list_head *)&config->planes); > + if (length == 0) { > + *out_length = length; > + return NULL; > + } > + > + array = kmalloc_array(length, sizeof(*array), GFP_KERNEL); > + if (!array) > + return ERR_PTR(-ENOMEM); > + > + list_for_each_entry(plane_cfg, &config->planes, link) { > + array[n] = plane_cfg; > + n++; > + } > + > + *out_length = length; > + return array; > +} To join the comment on the test, I am not a big fan of creating a new list to return to the caller, for three reasons: - the caller needs to manage an other pointer; - the caller needs to understand that the content of the array is only valid if: the config is not freed, nobody else removed anything from the planes; - the caller may think this list always have the same order if he looks at the tests. I would prefer a simple macro to do an iteration over the config->planes list: (I did not test this macro, but you have this idea) #define vkms_config_iter_plane(config, plane_cfg) \ list_for_each_entry((plane_cfg), &(config).planes, link) This way: - no new pointer to manage; - if one day we have concurency issue, we just have to protect config, not config+all the planes; - there is no expected order. [...] > bool vkms_config_is_valid(struct vkms_config *config) > { > + if (!valid_plane_number(config)) > + return false; > + > + if (!valid_plane_type(config)) > + return false; > + > return true; > } I really like the idea to split the validation function, way simpler! [...] > +void vkms_config_destroy_plane(struct vkms_config_plane *plane_cfg) > +{ > + list_del(&plane_cfg->link); > + kfree(plane_cfg); > +} I would prefer a "standard" function pair, i.e.: add/remove or create/destroy, not add/destroy. For me it should be create/destroy, you create the plane by using a config, so it is clear it will be attached to it. If you choose add/remove, you should explains in the documentation that remove is also doing kfree. [...] > diff --git a/drivers/gpu/drm/vkms/vkms_output.c > b/drivers/gpu/drm/vkms/vkms_output.c [...] > @@ -11,61 +11,63 @@ int vkms_output_init(struct vkms_device *vkmsdev) > struct vkms_connector *connector; > struct drm_encoder *encoder; > struct vkms_output *output; > - struct vkms_plane *primary, *overlay, *cursor = NULL; > - int ret; > + struct vkms_plane *primary = NULL, *cursor = NULL; > + struct vkms_config_plane **plane_cfgs = NULL; > + size_t n_planes; > + int ret = 0; > int writeback; > unsigned int n; I think it could be interesting to have a vkms_config_is_valid call here. It will avoid raising DRM errors or create unexpected devices. It will also garantee in a later patch that vkms_config_crtc_get_primary_plane is a valid pointer. > - /* > - * Initialize used plane. One primary plane is required to perform the > composition. > - * > - * The overlay and cursor planes are not mandatory, but can be used to > perform complex > - * composition. > - */ > - primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY); > - if (IS_ERR(primary)) > - return PTR_ERR(primary); > + plane_cfgs = vkms_config_get_planes(vkmsdev->config, &n_planes); > + if (IS_ERR(plane_cfgs)) > + return PTR_ERR(plane_cfgs); If you agree on the iterator implementation, this code could be simplified a lot. > - if (vkmsdev->config->cursor) { > - cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR); > - if (IS_ERR(cursor)) > - return PTR_ERR(cursor); > + for (n = 0; n < n_planes; n++) { > + struct vkms_config_plane *plane_cfg; > + enum drm_plane_type type; > + > + plane_cfg = plane_cfgs[n]; > + type = vkms_config_plane_get_type(plane_cfg); > + > + plane_cfg->plane = vkms_plane_init(vkmsdev, type); Can we pass plane_cfg in vkms_plane_init? This way we don't have to touch vkms_output_init when adding new vkms_config_plane members. > + if (IS_ERR(plane_cfg->plane)) { > + DRM_DEV_ERROR(dev->dev, "Failed to init vkms plane\n"); > + ret = PTR_ERR(plane_cfg->plane); > + goto err_free; > + } > + > + if (type == DRM_PLANE_TYPE_PRIMARY) > + primary = plane_cfg->plane; > + else if (type == DRM_PLANE_TYPE_CURSOR) > + cursor = plane_cfg->plane; > } [...]
