Re: [PATCH v5 3/8] drm/omap: introduce omap_hw_overlay

From: Tomi Valkeinen
Date: Tue Oct 12 2021 - 04:03:44 EST

On 23/09/2021 10:06, Neil Armstrong wrote:
From: Benoit Parrot <bparrot@xxxxxx>

Split out the hardware overlay specifics from omap_plane.
To start, the hw overlays are statically assigned to planes.

The goal is to eventually assign hw overlays dynamically to planes
during plane->atomic_check() based on requested caps (scaling, YUV,
etc). And then perform hw overlay re-assignment if required.

Signed-off-by: Benoit Parrot <bparrot@xxxxxx>
Signed-off-by: Neil Armstrong <narmstrong@xxxxxxxxxxxx>
---
drivers/gpu/drm/omapdrm/Makefile | 1 +
drivers/gpu/drm/omapdrm/omap_drv.c | 9 ++-
drivers/gpu/drm/omapdrm/omap_drv.h | 4 ++
drivers/gpu/drm/omapdrm/omap_overlay.c | 87 ++++++++++++++++++++++++++
drivers/gpu/drm/omapdrm/omap_overlay.h | 31 +++++++++
drivers/gpu/drm/omapdrm/omap_plane.c | 42 ++++++-------
6 files changed, 151 insertions(+), 23 deletions(-)
create mode 100644 drivers/gpu/drm/omapdrm/omap_overlay.c
create mode 100644 drivers/gpu/drm/omapdrm/omap_overlay.h

diff --git a/drivers/gpu/drm/omapdrm/Makefile b/drivers/gpu/drm/omapdrm/Makefile
index 21e8277ff88f..710b4e0abcf0 100644
--- a/drivers/gpu/drm/omapdrm/Makefile
+++ b/drivers/gpu/drm/omapdrm/Makefile
@@ -9,6 +9,7 @@ omapdrm-y := omap_drv.o \
omap_debugfs.o \
omap_crtc.o \
omap_plane.o \
+ omap_overlay.o \
omap_encoder.o \
omap_fb.o \
omap_gem.o \
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.c b/drivers/gpu/drm/omapdrm/omap_drv.c
index f86e20578143..b994014b22e8 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.c
+++ b/drivers/gpu/drm/omapdrm/omap_drv.c
@@ -583,10 +583,14 @@ static int omapdrm_init(struct omap_drm_private *priv, struct device *dev)
omap_gem_init(ddev);
+ ret = omap_hwoverlays_init(priv);
+ if (ret)
+ goto err_gem_deinit;
+
ret = omap_modeset_init(ddev);
if (ret) {
dev_err(priv->dev, "omap_modeset_init failed: ret=%d\n", ret);
- goto err_gem_deinit;
+ goto err_free_overlays;
}
/* Initialize vblank handling, start with all CRTCs disabled. */
@@ -618,6 +622,8 @@ static int omapdrm_init(struct omap_drm_private *priv, struct device *dev)
omap_fbdev_fini(ddev);
err_cleanup_modeset:
omap_modeset_fini(ddev);
+err_free_overlays:
+ omap_hwoverlays_destroy(priv);
err_gem_deinit:
omap_gem_deinit(ddev);
destroy_workqueue(priv->wq);
@@ -642,6 +648,7 @@ static void omapdrm_cleanup(struct omap_drm_private *priv)
drm_atomic_helper_shutdown(ddev);
omap_modeset_fini(ddev);
+ omap_hwoverlays_destroy(priv);
omap_gem_deinit(ddev);
destroy_workqueue(priv->wq);
diff --git a/drivers/gpu/drm/omapdrm/omap_drv.h b/drivers/gpu/drm/omapdrm/omap_drv.h
index 591d4c273f02..b4d9c2062723 100644
--- a/drivers/gpu/drm/omapdrm/omap_drv.h
+++ b/drivers/gpu/drm/omapdrm/omap_drv.h
@@ -24,6 +24,7 @@
#include "omap_gem.h"
#include "omap_irq.h"
#include "omap_plane.h"
+#include "omap_overlay.h"
#define DBG(fmt, ...) DRM_DEBUG_DRIVER(fmt"\n", ##__VA_ARGS__)
#define VERB(fmt, ...) if (0) DRM_DEBUG_DRIVER(fmt, ##__VA_ARGS__) /* verbose debug */
@@ -57,6 +58,9 @@ struct omap_drm_private {
unsigned int num_planes;
struct drm_plane *planes[8];
+ unsigned int num_ovls;
+ struct omap_hw_overlay *overlays[8];
+
struct drm_fb_helper *fbdev;
struct workqueue_struct *wq;
diff --git a/drivers/gpu/drm/omapdrm/omap_overlay.c b/drivers/gpu/drm/omapdrm/omap_overlay.c
new file mode 100644
index 000000000000..2b1416d2aad2
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/omap_overlay.c
@@ -0,0 +1,87 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: Benoit Parrot, <bparrot@xxxxxx>

Extra comma there, and similar case below.

+ */
+
+#include <drm/drm_atomic.h>
+#include <drm/drm_atomic_helper.h>
+#include <drm/drm_plane_helper.h>
+
+#include "omap_dmm_tiler.h"
+#include "omap_drv.h"
+
+/*
+ * overlay funcs
+ */
+static const char * const overlay_id_to_name[] = {
+ [OMAP_DSS_GFX] = "gfx",
+ [OMAP_DSS_VIDEO1] = "vid1",
+ [OMAP_DSS_VIDEO2] = "vid2",
+ [OMAP_DSS_VIDEO3] = "vid3",
+};

I was expecting to see the name array to be removed from omap_plane.c as it's moved here, but that's not the case. Why is that? Especially as after this series these names make no sense with the planes.

+static void omap_overlay_destroy(struct omap_hw_overlay *overlay)
+{
+ kfree(overlay);
+}
+
+static struct omap_hw_overlay *omap_overlay_init(enum omap_plane_id overlay_id,
+ enum omap_overlay_caps caps)
+{
+ struct omap_hw_overlay *overlay;
+
+ overlay = kzalloc(sizeof(*overlay), GFP_KERNEL);
+ if (!overlay)
+ return ERR_PTR(-ENOMEM);
+
+ overlay->name = overlay_id_to_name[overlay_id];
+ overlay->overlay_id = overlay_id;
+ overlay->caps = caps;
+ /*
+ * When this is called priv->num_crtcs is not known yet.
+ * Use a safe mask value to start with, it will get updated to the
+ * proper value after the first use.
+ */
+ overlay->possible_crtcs = 0xff;

This sounds like a hack. Why do we need possible_crtcs anyway? If I'm not mistaken, on all DSS versions any overlay can be used on any ctrtc. On the DRM plane level we need the possible_crtc as the DRM framework needs that (i.e. we just always set all crtcs available for all planes), but why is it needed here?

+ return overlay;
+}
+
+int omap_hwoverlays_init(struct omap_drm_private *priv)
+{
+ static const enum omap_plane_id hw_plane_ids[] = {
+ OMAP_DSS_GFX, OMAP_DSS_VIDEO1,
+ OMAP_DSS_VIDEO2, OMAP_DSS_VIDEO3,
+ };
+ u32 num_overlays = dispc_get_num_ovls(priv->dispc);
+ enum omap_overlay_caps caps;
+ int i, ret;
+
+ for (i = 0; i < num_overlays; i++) {
+ struct omap_hw_overlay *overlay;
+
+ caps = dispc_ovl_get_caps(priv->dispc, hw_plane_ids[i]);
+ overlay = omap_overlay_init(hw_plane_ids[i], caps);
+ if (IS_ERR(overlay)) {
+ ret = PTR_ERR(overlay);
+ dev_err(priv->dev, "failed to construct overlay for %s (%d)\n",
+ overlay_id_to_name[i], ret);
+ return ret;
+ }

I think this leaks memory if omap_overlay_init() fails.

+ overlay->idx = priv->num_ovls;
+ priv->overlays[priv->num_ovls++] = overlay;
+ }
+
+ return 0;
+}
+
+void omap_hwoverlays_destroy(struct omap_drm_private *priv)
+{
+ int i;
+
+ for (i = 0; i < priv->num_ovls; i++) {
+ omap_overlay_destroy(priv->overlays[i]);
+ priv->overlays[i] = NULL;
+ }
+}
diff --git a/drivers/gpu/drm/omapdrm/omap_overlay.h b/drivers/gpu/drm/omapdrm/omap_overlay.h
new file mode 100644
index 000000000000..892fecb67adb
--- /dev/null
+++ b/drivers/gpu/drm/omapdrm/omap_overlay.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 Texas Instruments Incorporated - http://www.ti.com/
+ * Author: Benoit Parrot, <bparrot@xxxxxx>
+ */
+
+#ifndef __OMAPDRM_OVERLAY_H__
+#define __OMAPDRM_OVERLAY_H__
+
+#include <linux/types.h>
+
+enum drm_plane_type;
+
+struct drm_device;
+struct drm_mode_object;
+struct drm_plane;
+
+/* Used to associate a HW overlay/plane to a plane */
+struct omap_hw_overlay {
+ int idx;

unsigned int.

+
+ const char *name;
+ enum omap_plane_id overlay_id;

Perhaps just "id" is fine. You don't have "overlay_name" there either, but just "name".

Tomi