drm/mgag200: Remove vidrst callbacks from struct mgag200_device_funcs

The callbacks disable_vidrst and enable_vidrst are obsolete. Remove
the fields from struct mgag200_device_funcs. Instead call their
implementations directly of the field 'has_vidrst' has been set in
struct mgag200_device_info.

Also change the logic slightly. The BMC used to start and stop scanout
during the CRTC's atomic_enable and atomic_disable. Plane updates were
done while the BMC scanned out the display. Now only stop once in
atomic_disable at the beginning of a modeset and then restart the
scanout at the end of a modeset in atomic_enable. While the modeset
takes place, the BMC does not scanout at all.
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240711072415.11831-3-tzimmermann@suse.de

drivers/gpu/drm/mgag200/mgag200_drv.h

@@ -247,18 +247,6 @@ struct mgag200_device_info {
 	}
 
 struct mgag200_device_funcs {
-	/*
-	 * Disables an external reset source (i.e., BMC) before programming
-	 * a new display mode.
-	 */
-	void (*disable_vidrst)(struct mga_device *mdev);
-
-	/*
-	 * Enables an external reset source (i.e., BMC) after programming
-	 * a new display mode.
-	 */
-	void (*enable_vidrst)(struct mga_device *mdev);
-
 	/*
 	 * Validate that the given state can be programmed into PIXPLLC. On
 	 * success, the calculated parameters should be stored in the CRTC's

drivers/gpu/drm/mgag200/mgag200_g200er.c

@@ -191,9 +191,6 @@ static void mgag200_g200er_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	const struct drm_format_info *format = mgag200_crtc_state->format;
 
-	if (funcs->disable_vidrst)
-		funcs->disable_vidrst(mdev);
-
 	mgag200_set_format_regs(mdev, format);
 	mgag200_set_mode_regs(mdev, adjusted_mode, mgag200_crtc_state->set_vidrst);
 
@@ -209,8 +206,8 @@ static void mgag200_g200er_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 
 	mgag200_enable_display(mdev);
 
-	if (funcs->enable_vidrst)
-		funcs->enable_vidrst(mdev);
+	if (mdev->info->has_vidrst)
+		mgag200_bmc_enable_vidrst(mdev);
 }
 
 static const struct drm_crtc_helper_funcs mgag200_g200er_crtc_helper_funcs = {

drivers/gpu/drm/mgag200/mgag200_g200ev.c

@@ -192,9 +192,6 @@ static void mgag200_g200ev_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	const struct drm_format_info *format = mgag200_crtc_state->format;
 
-	if (funcs->disable_vidrst)
-		funcs->disable_vidrst(mdev);
-
 	mgag200_set_format_regs(mdev, format);
 	mgag200_set_mode_regs(mdev, adjusted_mode, mgag200_crtc_state->set_vidrst);
 
@@ -210,8 +207,8 @@ static void mgag200_g200ev_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 
 	mgag200_enable_display(mdev);
 
-	if (funcs->enable_vidrst)
-		funcs->enable_vidrst(mdev);
+	if (mdev->info->has_vidrst)
+		mgag200_bmc_enable_vidrst(mdev);
 }
 
 static const struct drm_crtc_helper_funcs mgag200_g200ev_crtc_helper_funcs = {

drivers/gpu/drm/mgag200/mgag200_g200ew3.c

@@ -146,8 +146,6 @@ static const struct mgag200_device_info mgag200_g200ew3_device_info =
 	MGAG200_DEVICE_INFO_INIT(2048, 2048, 0, true, 0, 1, false);
 
 static const struct mgag200_device_funcs mgag200_g200ew3_device_funcs = {
-	.disable_vidrst = mgag200_bmc_disable_vidrst,
-	.enable_vidrst = mgag200_bmc_enable_vidrst,
 	.pixpllc_atomic_check = mgag200_g200ew3_pixpllc_atomic_check,
 	.pixpllc_atomic_update = mgag200_g200wb_pixpllc_atomic_update, // same as G200WB
 };

drivers/gpu/drm/mgag200/mgag200_g200se.c

@@ -323,9 +323,6 @@ static void mgag200_g200se_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	const struct drm_format_info *format = mgag200_crtc_state->format;
 
-	if (funcs->disable_vidrst)
-		funcs->disable_vidrst(mdev);
-
 	mgag200_set_format_regs(mdev, format);
 	mgag200_set_mode_regs(mdev, adjusted_mode, mgag200_crtc_state->set_vidrst);
 
@@ -341,8 +338,8 @@ static void mgag200_g200se_crtc_helper_atomic_enable(struct drm_crtc *crtc,
 
 	mgag200_enable_display(mdev);
 
-	if (funcs->enable_vidrst)
-		funcs->enable_vidrst(mdev);
+	if (mdev->info->has_vidrst)
+		mgag200_bmc_enable_vidrst(mdev);
 }
 
 static const struct drm_crtc_helper_funcs mgag200_g200se_crtc_helper_funcs = {

drivers/gpu/drm/mgag200/mgag200_g200wb.c

@@ -280,8 +280,6 @@ static const struct mgag200_device_info mgag200_g200wb_device_info =
 	MGAG200_DEVICE_INFO_INIT(1280, 1024, 31877, true, 0, 1, false);
 
 static const struct mgag200_device_funcs mgag200_g200wb_device_funcs = {
-	.disable_vidrst = mgag200_bmc_disable_vidrst,
-	.enable_vidrst = mgag200_bmc_enable_vidrst,
 	.pixpllc_atomic_check = mgag200_g200wb_pixpllc_atomic_check,
 	.pixpllc_atomic_update = mgag200_g200wb_pixpllc_atomic_update,
 };

drivers/gpu/drm/mgag200/mgag200_mode.c

@@ -655,9 +655,6 @@ void mgag200_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_
 	struct mgag200_crtc_state *mgag200_crtc_state = to_mgag200_crtc_state(crtc_state);
 	const struct drm_format_info *format = mgag200_crtc_state->format;
 
-	if (funcs->disable_vidrst)
-		funcs->disable_vidrst(mdev);
-
 	mgag200_set_format_regs(mdev, format);
 	mgag200_set_mode_regs(mdev, adjusted_mode, mgag200_crtc_state->set_vidrst);
 
@@ -671,22 +668,18 @@ void mgag200_crtc_helper_atomic_enable(struct drm_crtc *crtc, struct drm_atomic_
 
 	mgag200_enable_display(mdev);
 
-	if (funcs->enable_vidrst)
-		funcs->enable_vidrst(mdev);
+	if (mdev->info->has_vidrst)
+		mgag200_bmc_enable_vidrst(mdev);
 }
 
 void mgag200_crtc_helper_atomic_disable(struct drm_crtc *crtc, struct drm_atomic_state *old_state)
 {
 	struct mga_device *mdev = to_mga_device(crtc->dev);
-	const struct mgag200_device_funcs *funcs = mdev->funcs;
 
-	if (funcs->disable_vidrst)
-		funcs->disable_vidrst(mdev);
+	if (mdev->info->has_vidrst)
+		mgag200_bmc_disable_vidrst(mdev);
 
 	mgag200_disable_display(mdev);
-
-	if (funcs->enable_vidrst)
-		funcs->enable_vidrst(mdev);
 }
 
 void mgag200_crtc_reset(struct drm_crtc *crtc)