[PATCH v2 4/5] drm/modes: Parse overscan properties

[Maxime Ripard]

Properly configuring the overscan properties might be needed for the
initial setup of the framebuffer for display that still have overscan.
Let's allow for more properties on the kernel command line to setup each
margin.

Signed-off-by: Maxime Ripard <maxime.ripard at bootlin.com>
---
 drivers/gpu/drm/drm_fb_helper.c | 47 ++++++++++++++++++++++++++++++++++-
 drivers/gpu/drm/drm_modes.c     | 44 ++++++++++++++++++++++++++++++++-
 include/drm/drm_connector.h     |  1 +-
 3 files changed, 92 insertions(+)

diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
index 8781897559b2..4e403fe1f451 100644
--- a/drivers/gpu/drm/drm_fb_helper.c
+++ b/drivers/gpu/drm/drm_fb_helper.c
@@ -2567,6 +2567,51 @@ static void drm_setup_crtc_rotation(struct drm_fb_helper *fb_helper,
 	fb_helper->sw_rotations |= DRM_MODE_ROTATE_0;
 }
 
+static void drm_setup_connector_margins(struct drm_connector *connector)
+{
+	struct drm_cmdline_mode *cmdline = &connector->cmdline_mode;
+	struct drm_modeset_acquire_ctx ctx;
+	struct drm_atomic_state *state;
+	struct drm_device *dev = connector->dev;
+	int ret;
+
+	if (!drm_drv_uses_atomic_modeset(dev))
+		return;
+
+	drm_modeset_acquire_init(&ctx, 0);
+
+	state = drm_atomic_state_alloc(dev);
+	state->acquire_ctx = &ctx;
+
+retry:
+	drm_atomic_set_property(state, &connector->base,
+				dev->mode_config.tv_left_margin_property,
+				cmdline->overscan_left);
+
+	drm_atomic_set_property(state, &connector->base,
+				dev->mode_config.tv_right_margin_property,
+				cmdline->overscan_right);
+
+	drm_atomic_set_property(state, &connector->base,
+				dev->mode_config.tv_top_margin_property,
+				cmdline->overscan_top);
+
+	drm_atomic_set_property(state, &connector->base,
+				dev->mode_config.tv_bottom_margin_property,
+				cmdline->overscan_bottom);
+
+	ret = drm_atomic_commit(state);
+	if (ret == -EDEADLK) {
+		drm_atomic_state_clear(state);
+		drm_modeset_backoff(&ctx);
+		goto retry;
+	}
+
+	drm_atomic_state_put(state);
+	drm_modeset_drop_locks(&ctx);
+	drm_modeset_acquire_fini(&ctx);
+}
+
 static void drm_setup_crtcs(struct drm_fb_helper *fb_helper,
 			    u32 width, u32 height)
 {
@@ -2680,6 +2725,8 @@ static void drm_setup_crtcs_fb(struct drm_fb_helper *fb_helper)
 		struct drm_connector *connector =
 					fb_helper->connector_info[i]->connector;
 
+		drm_setup_connector_margins(connector);
+
 		/* use first connected connector for the physical dimensions */
 		if (connector->status == connector_status_connected) {
 			info->var.width = connector->display_info.width_mm;
diff --git a/drivers/gpu/drm/drm_modes.c b/drivers/gpu/drm/drm_modes.c
index ac8d70b92b62..493ba3ccde70 100644
--- a/drivers/gpu/drm/drm_modes.c
+++ b/drivers/gpu/drm/drm_modes.c
@@ -1586,6 +1586,50 @@ static int drm_mode_parse_cmdline_options(char *str, size_t len,
 		} else if (!strncmp(option, "reflect_y", delim - option)) {
 			rotation |= DRM_MODE_REFLECT_Y;
 			sep = delim;
+		} else if (!strncmp(option, "overscan_right", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->overscan_right = margin;
+		} else if (!strncmp(option, "overscan_left", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->overscan_left = margin;
+		} else if (!strncmp(option, "overscan_top", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->overscan_top = margin;
+		} else if (!strncmp(option, "overscan_bottom", delim - option)) {
+			const char *value = delim + 1;
+			unsigned int margin;
+
+			margin = simple_strtol(value, &sep, 10);
+
+			/* Make sure we have parsed something */
+			if (sep == value)
+				return -EINVAL;
+
+			mode->overscan_bottom = margin;
 		} else {
 			return -EINVAL;
 		}
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index dfe7f2304b35..44d9885dd401 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -903,6 +903,7 @@ struct drm_cmdline_mode {
 	int xres, yres;
 	int bpp;
 	int refresh;
+	int overscan_right, overscan_top, overscan_left, overscan_bottom;
 	bool rb;
 	bool interlace;
 	bool cvt;
-- 
git-series 0.9.1