Re: [RFC PATCH 3/3] drm/vkms: add overlay support

On 02/22, Daniel Vetter wrote:

On Sat, Feb 20, 2021 at 11:42:12AM -0300, Melissa Wen wrote:

...

Add support to overlay plane, in addition to primary and cursor planes. In this approach, the plane composition still requires an active primary plane and planes are composed associatively in the order: (primary <- overlay) <- cursor

It enables to run the following IGT tests successfully:

• kms_plane_cursor:
  • pipe-A-[overlay, primary, viewport]-size-[64, 128, 256]
• kms_atomic:
  • plane-overlay-legacy

and preserves the successful execution of kms_cursor_crc, kms_writeback and kms_flip

Signed-off-by: Melissa Wen melissa.srw@gmail.com

drivers/gpu/drm/vkms/vkms_composer.c | 27 +++++++++++++++++---------- drivers/gpu/drm/vkms/vkms_drv.c | 5 +++++ drivers/gpu/drm/vkms/vkms_drv.h | 1 + drivers/gpu/drm/vkms/vkms_output.c | 17 +++++++++++++++-- drivers/gpu/drm/vkms/vkms_plane.c | 20 +++++++++++++++----- 5 files changed, 53 insertions(+), 17 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index be8f1d33c645..2116da9b5a43 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -144,11 +144,12 @@ static void compose_planes(struct vkms_composer *primary_composer,

static int composite(void **vaddr_out, struct vkms_composer *primary_composer,

•      struct vkms_composer *cursor_composer)
  

•      struct vkms_crtc_state *crtc_state)
  

{ struct drm_framebuffer *fb = &primary_composer->fb; struct drm_gem_object *gem_obj = drm_gem_fb_get_obj(fb, 0); struct drm_gem_shmem_object *shmem_obj = to_drm_gem_shmem_obj(gem_obj);

• int i;

  if (!*vaddr_out) { *vaddr_out = kzalloc(shmem_obj->base.size, GFP_KERNEL);

@@ -163,8 +164,14 @@ static int composite(void **vaddr_out,

memcpy(*vaddr_out, shmem_obj->vaddr, shmem_obj->base.size);

• if (cursor_composer)

• compose_planes(primary_composer, cursor_composer, *vaddr_out);
  

• /* If there are other planes besides primary, we consider the active

• * planes should be in z-order and compose them associatively:
  

• * ((primary <- overlay) <- cursor)
  

• */
  

• for (i = 1; i < crtc_state->num_active_planes; i++)

• compose_planes(primary_composer,
  

• 	       crtc_state->active_planes[i]->composer,
  

• 	       *vaddr_out);
  
  

  return 0;

} @@ -186,7 +193,7 @@ void vkms_composer_worker(struct work_struct *work) struct drm_crtc *crtc = crtc_state->base.crtc; struct vkms_output *out = drm_crtc_to_vkms_output(crtc); struct vkms_composer *primary_composer = NULL;

• struct vkms_composer *cursor_composer = NULL;

• struct vkms_plane_state *act_plane = NULL; bool crc_pending, wb_pending; void *vaddr_out = NULL; u32 crc32 = 0;

@@ -210,11 +217,11 @@ void vkms_composer_worker(struct work_struct *work) if (!crc_pending) return;

• if (crtc_state->num_active_planes >= 1)

• primary_composer = crtc_state->active_planes[0]->composer;
  

• if (crtc_state->num_active_planes == 2)

• cursor_composer = crtc_state->active_planes[1]->composer;
  

• if (crtc_state->num_active_planes >= 1) {

• act_plane = crtc_state->active_planes[0];
  

• if (act_plane->base.plane->type == DRM_PLANE_TYPE_PRIMARY)
  

• 	primary_composer = act_plane->composer;
  

• }

  if (!primary_composer) return;

@@ -222,7 +229,7 @@ void vkms_composer_worker(struct work_struct *work) if (wb_pending) vaddr_out = crtc_state->active_writeback;

• ret = composite(&vaddr_out, primary_composer, cursor_composer);

• ret = composite(&vaddr_out, primary_composer, crtc_state); if (ret) { if (ret == -EINVAL && !wb_pending) kfree(vaddr_out);

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c index 2173b82606f6..027ffe759440 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.c +++ b/drivers/gpu/drm/vkms/vkms_drv.c @@ -44,6 +44,10 @@ static bool enable_writeback = true; module_param_named(enable_writeback, enable_writeback, bool, 0444); MODULE_PARM_DESC(enable_writeback, "Enable/Disable writeback connector support");

+static bool enable_overlay; +module_param_named(enable_overlay, enable_overlay, bool, 0444); +MODULE_PARM_DESC(enable_overlay, "Enable/Disable overlay support");

DEFINE_DRM_GEM_FOPS(vkms_driver_fops);

static void vkms_release(struct drm_device *dev) @@ -198,6 +202,7 @@ static int __init vkms_init(void)

config->cursor = enable_cursor; config->writeback = enable_writeback;

• config->overlay = enable_overlay;

  return vkms_create(config);

} diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index 9ad5ad8b7737..784219da8df0 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -85,6 +85,7 @@ struct vkms_device; struct vkms_config { bool writeback; bool cursor;

• bool overlay; /* only set when instantiated */ struct vkms_device *dev;

}; diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c index 05d3bb45e6c1..c60d0f2e7a37 100644 --- a/drivers/gpu/drm/vkms/vkms_output.c +++ b/drivers/gpu/drm/vkms/vkms_output.c @@ -39,7 +39,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index) struct drm_connector *connector = &output->connector; struct drm_encoder *encoder = &output->encoder; struct drm_crtc *crtc = &output->crtc;

• struct drm_plane *primary, *cursor = NULL;

• struct drm_plane *primary, *cursor = NULL, *overlay = NULL; int ret; int writeback;

@@ -51,6 +51,16 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index) if (ret) goto err_crtc;

• if (vkmsdev->config->overlay) {

• overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY, index);
  

• if (IS_ERR(overlay)) {
  

• 	ret = PTR_ERR(overlay);
  

• 	goto err_overlay;
  

• }
  

• if (overlay && !overlay->possible_crtcs)
  

• 	overlay->possible_crtcs = drm_crtc_mask(crtc);
  

• }
• if (vkmsdev->config->cursor) { cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index); if (IS_ERR(cursor)) {

@@ -58,7 +68,6 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index) goto err_cursor; } }

• crtc->cursor = cursor; if (cursor && !cursor->possible_crtcs) cursor->possible_crtcs = drm_crtc_mask(crtc);

@@ -108,6 +117,10 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index) if (vkmsdev->config->cursor) drm_plane_cleanup(cursor);

+err_overlay:

• if (vkmsdev->config->overlay)

• drm_plane_cleanup(overlay);
  

Using drmm_universal_plane_init would be nice so we can ditch a bunch of this cleanup code, but can be done later. Same for crtc.

Hmm.. I'll check it. Just to be sure, would it be drmm_universal_plane_alloc?

...

err_crtc: drm_plane_cleanup(primary);

diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c index 0824327cc860..8e7bb84bc894 100644 --- a/drivers/gpu/drm/vkms/vkms_plane.c +++ b/drivers/gpu/drm/vkms/vkms_plane.c @@ -19,6 +19,11 @@ static const u32 vkms_cursor_formats[] = { DRM_FORMAT_ARGB8888, };

+static const u32 vkms_overlay_formats[] = {

• DRM_FORMAT_ARGB8888,
• DRM_FORMAT_XRGB8888,

Does the blend function correctly work for XRGB, i.e. ignore the alpha channel? Maybe even split that functionality out into a separate patch (and then also add it for the cursor plane, so we keep one unified format list for non-primary planes) so it sticks out more.

Initially, I was also reusing the cursor formart, because ARGB makes more sense to me. But I checked that IGT considers a XRGB overlay, that is why I included both. I verified in tests using XRGB that the color is received as a full-opaque RGB: [FF-RR-GG-BB] and the alpha_blending function composes these two types correctly. If this is the regular behavior for XRGB, I think I can unify cursor and overlay formats in the previous patch that generalize some cursor variables for reusing.

...

+};

static struct drm_plane_state * vkms_plane_duplicate_state(struct drm_plane *plane) { @@ -127,7 +132,7 @@ static int vkms_plane_atomic_check(struct drm_plane *plane, if (IS_ERR(crtc_state)) return PTR_ERR(crtc_state);

• if (plane->type == DRM_PLANE_TYPE_CURSOR)

• if (plane->type != DRM_PLANE_TYPE_PRIMARY) can_position = true;

  ret = drm_atomic_helper_check_plane_state(state, crtc_state,

@@ -195,14 +200,19 @@ struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev, int ret, nformats;

plane = kzalloc(sizeof(*plane), GFP_KERNEL);

• if (!plane)

• return ERR_PTR(-ENOMEM);
  
  

• if (type == DRM_PLANE_TYPE_CURSOR) {

• switch (type) {
• case DRM_PLANE_TYPE_CURSOR: formats = vkms_cursor_formats; nformats = ARRAY_SIZE(vkms_cursor_formats); funcs = &vkms_primary_helper_funcs;

• } else {

• break;
  

• case DRM_PLANE_TYPE_OVERLAY:

• formats = vkms_overlay_formats;
  

• nformats = ARRAY_SIZE(vkms_overlay_formats);
  

• funcs = &vkms_primary_helper_funcs;
  

• break;
  

• default: formats = vkms_formats; nformats = ARRAY_SIZE(vkms_formats); funcs = &vkms_primary_helper_funcs;

Tbf my brain is somewhat toast today, but aside from the few questions I think this looks like a solid approach.

Thanks for review. I'll address the improvements you pointed out here and send a new version.

Melissa

Cheers, Daniel

Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch