Re: [PATCH v3] drm/vkms: Remove index parameter from init_vkms_output

Maíra Canal <mcanal@xxxxxxxxxx> · Wed, 20 Nov 2024 07:02:39 -0300

On 19/11/24 10:56, Louis Chauvet wrote:
On 19/11/24 - 14:34, Louis Chauvet wrote:
VKMS currently supports only one CRTC, so it make no sense to have this
index configurable. To avoid issues, replace this hardcoded index by
drm_crtc_mask when applicable.

There is no need to manually set a crtc mask on primary and cursor plane
as it is automatically set by drmm_crtc_alloc_with_planes.

In addition, this will remove the use of an uninitialized structure in
vkms_add_overlay_plane. This currently works by chance because two things:
- vkms_plane_init always set a possible_crtcs value, so the problematic
   branch is never used;
- drm_crtc_mask on an kzalloc'd drm_crtc returns BIT(0), and the VKMS CRTC
   always have this id.

Signed-off-by: Louis Chauvet <louis.chauvet@xxxxxxxxxxx>

Hi Maíra, José,

You told me "LGTM" for the v2, but without leaving a Acked/Reviewed-by,
should I add them? Or maybe you prefer to formally send them now?

Reviewed-by: Maíra Canal <mcanal@xxxxxxxxxx>

Best Regards,
- Maíra


Thanks,
Louis Chauvet

---
Changes in v3:
- Rebased on drm-misc-next
- Link to v2: https://lore.kernel.org/r/20241010-vkms-remove-index-v2-1-6b8d6cfd5a15@xxxxxxxxxxx

Changes in v2:
- Applied comments from José
- Link to v1: https://lore.kernel.org/r/20240906-vkms-remove-index-v1-1-3cfedd8ccb2f@xxxxxxxxxxx
---
  drivers/gpu/drm/vkms/vkms_drv.c    |  2 +-
  drivers/gpu/drm/vkms/vkms_drv.h    |  8 ++-----
  drivers/gpu/drm/vkms/vkms_output.c | 49 +++++++++++++-------------------------
  drivers/gpu/drm/vkms/vkms_plane.c  |  4 ++--
  4 files changed, 21 insertions(+), 42 deletions(-)

diff --git a/drivers/gpu/drm/vkms/vkms_drv.c b/drivers/gpu/drm/vkms/vkms_drv.c
index bab13943d8e0085bed85092d7bc8727d834768a9..e4ae69d9ef871c9ce436ad0bd8c6551d8fe7f55c 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.c
+++ b/drivers/gpu/drm/vkms/vkms_drv.c
@@ -174,7 +174,7 @@ static int vkms_modeset_init(struct vkms_device *vkmsdev)
  	dev->mode_config.preferred_depth = 0;
  	dev->mode_config.helper_private = &vkms_mode_config_helpers;
  
-	return vkms_output_init(vkmsdev, 0);
+	return vkms_output_init(vkmsdev);
  }
  
  static int vkms_create(struct vkms_config *config)
diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h
index 672fe191e239c03e7358d43eb19215361417a781..036101ee4ea1cb0a335cd2ea78a8ca9da87fbe93 100644
--- a/drivers/gpu/drm/vkms/vkms_drv.h
+++ b/drivers/gpu/drm/vkms/vkms_drv.h
@@ -212,21 +212,17 @@ int vkms_crtc_init(struct drm_device *dev, struct drm_crtc *crtc,
   * vkms_output_init() - Initialize all sub-components needed for a VKMS device.
   *
   * @vkmsdev: VKMS device to initialize
- * @index: CRTC which can be attached to the planes. The caller must ensure that
- *	   @index is positive and less or equals to 31.
   */
-int vkms_output_init(struct vkms_device *vkmsdev, int index);
+int vkms_output_init(struct vkms_device *vkmsdev);
  
  /**
   * vkms_plane_init() - Initialize a plane
   *
   * @vkmsdev: VKMS device containing the plane
   * @type: type of plane to initialize
- * @index: CRTC which can be attached to the plane. The caller must ensure that
- *	   @index is positive and less or equals to 31.
   */
  struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
-				   enum drm_plane_type type, int index);
+				   enum drm_plane_type type);
  
  /* CRC Support */
  const char *const *vkms_get_crc_sources(struct drm_crtc *crtc,
diff --git a/drivers/gpu/drm/vkms/vkms_output.c b/drivers/gpu/drm/vkms/vkms_output.c
index 25a99fde126c7402941954015287ab0887484139..8f4bd5aef087b459d37d0cbbf90fe0145090917a 100644
--- a/drivers/gpu/drm/vkms/vkms_output.c
+++ b/drivers/gpu/drm/vkms/vkms_output.c
@@ -32,29 +32,14 @@ static const struct drm_connector_helper_funcs vkms_conn_helper_funcs = {
  	.get_modes    = vkms_conn_get_modes,
  };
  
-static int vkms_add_overlay_plane(struct vkms_device *vkmsdev, int index,
-				  struct drm_crtc *crtc)
-{
-	struct vkms_plane *overlay;
-
-	overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY, index);
-	if (IS_ERR(overlay))
-		return PTR_ERR(overlay);
-
-	if (!overlay->base.possible_crtcs)
-		overlay->base.possible_crtcs = drm_crtc_mask(crtc);
-
-	return 0;
-}
-
-int vkms_output_init(struct vkms_device *vkmsdev, int index)
+int vkms_output_init(struct vkms_device *vkmsdev)
  {
  	struct vkms_output *output = &vkmsdev->output;
  	struct drm_device *dev = &vkmsdev->drm;
  	struct drm_connector *connector = &output->connector;
  	struct drm_encoder *encoder = &output->encoder;
  	struct drm_crtc *crtc = &output->crtc;
-	struct vkms_plane *primary, *cursor = NULL;
+	struct vkms_plane *primary, *overlay, *cursor = NULL;
  	int ret;
  	int writeback;
  	unsigned int n;
@@ -65,29 +50,31 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
  	 * 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, index);
+	primary = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_PRIMARY);
  	if (IS_ERR(primary))
  		return PTR_ERR(primary);
  
-	if (vkmsdev->config->overlay) {
-		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
-			ret = vkms_add_overlay_plane(vkmsdev, index, crtc);
-			if (ret)
-				return ret;
-		}
-	}
-
  	if (vkmsdev->config->cursor) {
-		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR, index);
+		cursor = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_CURSOR);
  		if (IS_ERR(cursor))
  			return PTR_ERR(cursor);
  	}
  
-	/* [1]: Allocation of a CRTC, its index will be BIT(0) = 1 */
  	ret = vkms_crtc_init(dev, crtc, &primary->base, &cursor->base);
  	if (ret)
  		return ret;
  
+	if (vkmsdev->config->overlay) {
+		for (n = 0; n < NUM_OVERLAY_PLANES; n++) {
+			overlay = vkms_plane_init(vkmsdev, DRM_PLANE_TYPE_OVERLAY);
+			if (IS_ERR(overlay)) {
+				DRM_DEV_ERROR(dev->dev, "Failed to init vkms plane\n");
+				return PTR_ERR(overlay);
+			}
+			overlay->base.possible_crtcs = drm_crtc_mask(crtc);
+		}
+	}
+
  	ret = drm_connector_init(dev, connector, &vkms_connector_funcs,
  				 DRM_MODE_CONNECTOR_VIRTUAL);
  	if (ret) {
@@ -103,11 +90,7 @@ int vkms_output_init(struct vkms_device *vkmsdev, int index)
  		DRM_ERROR("Failed to init encoder\n");
  		goto err_encoder;
  	}
-	/*
-	 * This is a hardcoded value to select crtc for the encoder.
-	 * BIT(0) here designate the first registered CRTC, the one allocated in [1]
-	 */
-	encoder->possible_crtcs = BIT(0);
+	encoder->possible_crtcs = drm_crtc_mask(crtc);
  
  	ret = drm_connector_attach_encoder(connector, encoder);
  	if (ret) {
diff --git a/drivers/gpu/drm/vkms/vkms_plane.c b/drivers/gpu/drm/vkms/vkms_plane.c
index e5c625ab8e3e06cb95f468c59bc3b06ef85eab6f..ad137c9a75f5e9ee3bb62e7bb2c5e3684a6ecbb6 100644
--- a/drivers/gpu/drm/vkms/vkms_plane.c
+++ b/drivers/gpu/drm/vkms/vkms_plane.c
@@ -198,12 +198,12 @@ static const struct drm_plane_helper_funcs vkms_plane_helper_funcs = {
  };
  
  struct vkms_plane *vkms_plane_init(struct vkms_device *vkmsdev,
-				   enum drm_plane_type type, int index)
+				   enum drm_plane_type type)
  {
  	struct drm_device *dev = &vkmsdev->drm;
  	struct vkms_plane *plane;
  
-	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 1 << index,
+	plane = drmm_universal_plane_alloc(dev, struct vkms_plane, base, 0,
  					   &vkms_plane_funcs,
  					   vkms_formats, ARRAY_SIZE(vkms_formats),
  					   NULL, type, NULL);

---
base-commit: 7d2faa8dbb7055a115fe0cd6068d7090094a573d
change-id: 20240906-vkms-remove-index-3a6e04c38e02

Best regards,
--
Louis Chauvet <louis.chauvet@xxxxxxxxxxx>








