drm/gma500: cleanup: drm_modeset_lock_all() --> DRM_MODESET_LOCK_ALL_BEGIN()

As requested in Documentation/gpu/todo.rst, replace driver calls to
drm_modeset_lock_all() with DRM_MODESET_LOCK_ALL_BEGIN() and
DRM_MODESET_LOCK_ALL_END()
Signed-off-by: Fernando Ramos <greenfoo@u92.eu>
Signed-off-by: Sean Paul <seanpaul@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210924064324.229457-15-greenfoo@u92.eu

drivers/gpu/drm/gma500/psb_device.c

@@ -8,6 +8,7 @@
 #include <linux/backlight.h>
 
 #include <drm/drm.h>
+#include <drm/drm_drv.h>
 
 #include "gma_device.h"
 #include "intel_bios.h"
@@ -169,8 +170,10 @@ static int psb_save_display_registers(struct drm_device *dev)
 {
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct drm_crtc *crtc;
+	struct drm_modeset_acquire_ctx ctx;
 	struct gma_connector *connector;
 	struct psb_state *regs = &dev_priv->regs.psb;
+	int ret;
 
 	/* Display arbitration control + watermarks */
 	regs->saveDSPARB = PSB_RVDC32(DSPARB);
@@ -183,7 +186,7 @@ static int psb_save_display_registers(struct drm_device *dev)
 	regs->saveCHICKENBIT = PSB_RVDC32(DSPCHICKENBIT);
 
 	/* Save crtc and output state */
-	drm_modeset_lock_all(dev);
+	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, ret);
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head) {
 		if (drm_helper_crtc_in_use(crtc))
 			dev_priv->ops->save_crtc(crtc);
@@ -193,8 +196,9 @@ static int psb_save_display_registers(struct drm_device *dev)
 		if (connector->save)
 			connector->save(&connector->base);
 
-	drm_modeset_unlock_all(dev);
-	return 0;
+	DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
+
+	return ret;
 }
 
 /**
@@ -207,8 +211,10 @@ static int psb_restore_display_registers(struct drm_device *dev)
 {
 	struct drm_psb_private *dev_priv = to_drm_psb_private(dev);
 	struct drm_crtc *crtc;
+	struct drm_modeset_acquire_ctx ctx;
 	struct gma_connector *connector;
 	struct psb_state *regs = &dev_priv->regs.psb;
+	int ret;
 
 	/* Display arbitration + watermarks */
 	PSB_WVDC32(regs->saveDSPARB, DSPARB);
@@ -223,7 +229,7 @@ static int psb_restore_display_registers(struct drm_device *dev)
 	/*make sure VGA plane is off. it initializes to on after reset!*/
 	PSB_WVDC32(0x80000000, VGACNTRL);
 
-	drm_modeset_lock_all(dev);
+	DRM_MODESET_LOCK_ALL_BEGIN(dev, ctx, 0, ret);
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
 		if (drm_helper_crtc_in_use(crtc))
 			dev_priv->ops->restore_crtc(crtc);
@@ -232,8 +238,8 @@ static int psb_restore_display_registers(struct drm_device *dev)
 		if (connector->restore)
 			connector->restore(&connector->base);
 
-	drm_modeset_unlock_all(dev);
-	return 0;
+	DRM_MODESET_LOCK_ALL_END(dev, ctx, ret);
+	return ret;
 }
 
 static int psb_power_down(struct drm_device *dev)