[PATCH 12/12] drm/mgag200: Compute PLL values during atomic check

[Thomas Zimmermann <tzimmermann@xxxxxxx>]

PLL setup can fail if the display mode's clock is not supported by
any PLL configuration. Compute the PLL values during atomic check, so
that atomic commits can fail at the appropriate time. If successful,
use the values in the atomic-update phase.

Signed-off-by: Thomas Zimmermann <tzimmermann@xxxxxxx>
---
 drivers/gpu/drm/mgag200/mgag200_drv.h  |  2 ++
 drivers/gpu/drm/mgag200/mgag200_mode.c | 20 +++++++++++++++++---
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/mgag200/mgag200_drv.h b/drivers/gpu/drm/mgag200/mgag200_drv.h
index c813d6c15f70..6473e9c037d0 100644
--- a/drivers/gpu/drm/mgag200/mgag200_drv.h
+++ b/drivers/gpu/drm/mgag200/mgag200_drv.h
@@ -129,6 +129,8 @@ struct mgag200_pll_values {
 
 struct mgag200_crtc_state {
 	struct drm_crtc_state base;
+
+	struct mgag200_pll_values pixpll;
 };
 
 static inline struct mgag200_crtc_state *to_mgag200_crtc_state(struct drm_crtc_state *base)
diff --git a/drivers/gpu/drm/mgag200/mgag200_mode.c b/drivers/gpu/drm/mgag200/mgag200_mode.c
index 6a5c419c6641..55c4f76175bd 100644
--- a/drivers/gpu/drm/mgag200/mgag200_mode.c
+++ b/drivers/gpu/drm/mgag200/mgag200_mode.c
@@ -1802,6 +1802,7 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 	struct drm_device *dev = crtc->dev;
 	struct mga_device *mdev = to_mga_device(dev);
 	struct drm_display_mode *adjusted_mode = &crtc_state->adjusted_mode;
+	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	struct drm_framebuffer *fb = plane_state->fb;
 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(plane_state);
 	struct drm_rect fullscreen = {
@@ -1810,15 +1811,13 @@ mgag200_simple_display_pipe_enable(struct drm_simple_display_pipe *pipe,
 		.y1 = 0,
 		.y2 = fb->height,
 	};
-	struct mgag200_pll_values pixpll;
 
 	if (mdev->type == G200_WB || mdev->type == G200_EW3)
 		mgag200_g200wb_hold_bmc(mdev);
 
 	mgag200_set_format_regs(mdev, fb);
 	mgag200_set_mode_regs(mdev, adjusted_mode);
-	mgag200_compute_pixpll_values(mdev, adjusted_mode->clock, &pixpll);
-	mgag200_set_pixpll(mdev, &pixpll);
+	mgag200_set_pixpll(mdev, &mgag200_crtc_state->pixpll);
 
 	if (mdev->type == G200_ER)
 		mgag200_g200er_reset_tagfifo(mdev);
@@ -1852,8 +1851,12 @@ mgag200_simple_display_pipe_check(struct drm_simple_display_pipe *pipe,
 				  struct drm_crtc_state *crtc_state)
 {
 	struct drm_plane *plane = plane_state->plane;
+	struct drm_device *dev = plane->dev;
+	struct mga_device *mdev = to_mga_device(dev);
+	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	struct drm_framebuffer *new_fb = plane_state->fb;
 	struct drm_framebuffer *fb = NULL;
+	int ret;
 
 	if (!new_fb)
 		return 0;
@@ -1864,6 +1867,13 @@ mgag200_simple_display_pipe_check(struct drm_simple_display_pipe *pipe,
 	if (!fb || (fb->format != new_fb->format))
 		crtc_state->mode_changed = true; /* update PLL settings */
 
+	if (crtc_state->mode_changed) {
+		ret = mgag200_compute_pixpll_values(mdev, crtc_state->mode.clock,
+						    &mgag200_crtc_state->pixpll);
+		if (ret)
+			return ret;
+	}
+
 	return 0;
 }
 
@@ -1891,6 +1901,7 @@ mgag200_simple_display_pipe_duplicate_crtc_state(struct drm_simple_display_pipe
 {
 	struct drm_crtc *crtc = &pipe->crtc;
 	struct drm_crtc_state *crtc_state = crtc->state;
+	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	struct mgag200_crtc_state *new_mgag200_crtc_state;
 
 	if (!crtc_state)
@@ -1901,6 +1912,9 @@ mgag200_simple_display_pipe_duplicate_crtc_state(struct drm_simple_display_pipe
 		return NULL;
 	__drm_atomic_helper_crtc_duplicate_state(crtc, &new_mgag200_crtc_state->base);
 
+	memcpy(&new_mgag200_crtc_state->pixpll, &mgag200_crtc_state->pixpll,
+	       sizeof(new_mgag200_crtc_state->pixpll));
+
 	return &new_mgag200_crtc_state->base;
 }
 
-- 
2.32.0