drm/nouveau: No need to lock/unlock the VGA CRTC regs all the time.

Locking only makes sense in the VBIOS parsing code as it's executed
before CRTC init.

Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 12 insertions, 24 deletions

diff --git a/drivers/gpu/drm/nouveau/nv04_display.c b/drivers/gpu/drm/nouveau/nv04_display.c
index 93200da..c6df391 100644
--- a/drivers/gpu/drm/nouveau/nv04_display.c
+++ b/drivers/gpu/drm/nouveau/nv04_display.c
@@ -32,8 +32,6 @@
 #include "nouveau_encoder.h"
 #include "nouveau_connector.h"
 
-#define MULTIPLE_ENCODERS(e) (e & (e - 1))
-
 static void
 nv04_display_store_initial_head_owner(struct drm_device *dev)
 {
@@ -41,7 +39,7 @@ nv04_display_store_initial_head_owner(struct drm_device *dev)
 
 	if (dev_priv->chipset != 0x11) {
 		dev_priv->crtc_owner = NVReadVgaCrtc(dev, 0, NV_CIO_CRE_44);
-		goto ownerknown;
+		return;
 	}
 
 	/* reading CR44 is broken on nv11, so we attempt to infer it */
@@ -52,8 +50,6 @@ nv04_display_store_initial_head_owner(struct drm_device *dev)
 		bool tvA = false;
 		bool tvB = false;
 
-		NVLockVgaCrtcs(dev, false);
-
 		slaved_on_B = NVReadVgaCrtc(dev, 1, NV_CIO_CRE_PIXEL_INDEX) &
 									0x80;
 		if (slaved_on_B)
@@ -66,8 +62,6 @@ nv04_display_store_initial_head_owner(struct drm_device *dev)
 			tvA = !(NVReadVgaCrtc(dev, 0, NV_CIO_CRE_LCD__INDEX) &
 					MASK(NV_CIO_CRE_LCD_LCD_SELECT));
 
-		NVLockVgaCrtcs(dev, true);
-
 		if (slaved_on_A && !tvA)
 			dev_priv->crtc_owner = 0x0;
 		else if (slaved_on_B && !tvB)
@@ -79,12 +73,6 @@ nv04_display_store_initial_head_owner(struct drm_device *dev)
 		else
 			dev_priv->crtc_owner = 0x0;
 	}
-
-ownerknown:
-	/* we need to ensure the heads are not tied henceforth, or reading any
-	 * 8 bit reg on head B will fail
-	 * setting a single arbitrary head solves that */
-	NVSetOwner(dev, 0);
 }
 
 int
@@ -99,8 +87,13 @@ nv04_display_create(struct drm_device *dev)
 
 	NV_DEBUG_KMS(dev, "\n");
 
-	if (nv_two_heads(dev))
+	NVLockVgaCrtcs(dev, false);
+
+	if (nv_two_heads(dev)) {
 		nv04_display_store_initial_head_owner(dev);
+		NVSetOwner(dev, 0);
+	}
+
 	nouveau_hw_save_vga_fonts(dev, 1);
 
 	drm_mode_config_init(dev);
@@ -168,8 +161,6 @@ nv04_display_create(struct drm_device *dev)
 	}
 
 	/* Save previous state */
-	NVLockVgaCrtcs(dev, false);
-
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
 		crtc->funcs->save(crtc);
 
@@ -185,6 +176,7 @@ nv04_display_create(struct drm_device *dev)
 void
 nv04_display_destroy(struct drm_device *dev)
 {
+	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct drm_encoder *encoder;
 	struct drm_crtc *crtc;
 
@@ -200,8 +192,6 @@ nv04_display_destroy(struct drm_device *dev)
 	}
 
 	/* Restore state */
-	NVLockVgaCrtcs(dev, false);
-
 	list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) {
 		struct drm_encoder_helper_funcs *func = encoder->helper_private;
 
@@ -214,12 +204,15 @@ nv04_display_destroy(struct drm_device *dev)
 	drm_mode_config_cleanup(dev);
 
 	nouveau_hw_save_vga_fonts(dev, 0);
+
+	if (nv_two_heads(dev))
+		NVSetOwner(dev, dev_priv->crtc_owner);
+	NVLockVgaCrtcs(dev, true);
 }
 
 void
 nv04_display_restore(struct drm_device *dev)
 {
-	struct drm_nouveau_private *dev_priv = dev->dev_private;
 	struct drm_encoder *encoder;
 	struct drm_crtc *crtc;
 
@@ -241,10 +234,5 @@ nv04_display_restore(struct drm_device *dev)
 
 	list_for_each_entry(crtc, &dev->mode_config.crtc_list, head)
 		crtc->funcs->restore(crtc);
-
-	if (nv_two_heads(dev))
-		NVSetOwner(dev, dev_priv->crtc_owner);
-
-	NVLockVgaCrtcs(dev, true);
 }