vmware/vmwgfx: Try to use only_hw_present semantics if screen targets are enabled

If screen targets are enabled and there is a reasonable chance that the vmwgfx
drm driver can use the surface backing a pixmap as a screen target surface,
then make that surface a modesetting framebuffer rather than the corresponding
DMA buffer. In practice this applies when we start scanning out from the
origin (0,0) of the pixmap. However, we would also like to apply the constraint
that the scanout area is the entire pixmap, since that is the constraint used
by the drm driver, but that would currently require drm framebuffer
reallocations and possible flicker, so disable that for now. The drm driver
will correctly handle the possibly oversized surface handed to it anyway, and
the cost we pay for this is an extra hardware copy of the dirtied area when
doing a software update of the scanout.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>

1 files changed, 20 insertions, 6 deletions

diff --git a/vmwgfx/vmwgfx_driver.c b/vmwgfx/vmwgfx_driver.c
index 2925227..48f8a63 100644
--- a/vmwgfx/vmwgfx_driver.c
+++ b/vmwgfx/vmwgfx_driver.c
@@ -541,6 +541,14 @@ drv_pre_init(ScrnInfoPtr pScrn, int flags)
 		   ms->drm_major, ms->drm_minor, ms->drm_patch);
     }
 
+    ms->has_screen_targets = ms->drm_major > 2 ||
+	(ms->drm_major == 2 && ms->drm_minor >= 7);
+    ms->has_screen_targets = (ms->has_screen_targets &&
+			      !vmwgfx_get_param(ms->fd,
+						DRM_VMW_PARAM_SCREEN_TARGET,
+						&cap) &&
+			      cap != 0);
+
     ms->check_fb_size = (vmwgfx_max_fb_size(ms->fd, &ms->max_fb_size) == 0);
 
     if (vmwgfx_get_param(ms->fd, DRM_VMW_PARAM_HW_CAPS, &cap) != 0) {
@@ -744,7 +752,7 @@ void xorg_flush(ScreenPtr pScreen)
 
 	if (vpix->fb_id != -1) {
 	    if (vpix->pending_update) {
-		if (ms->only_hw_presents &&
+		if (vpix->scanout_hw &&
 		    REGION_NOTEMPTY(pscreen, vpix->pending_update)) {
 		    (void) vmwgfx_hw_accel_validate(pixmap, 0, XA_FLAG_SCANOUT,
 						    0, NULL);
@@ -756,7 +764,7 @@ void xorg_flush(ScreenPtr pScreen)
 		REGION_EMPTY(pScreen, vpix->pending_update);
 	    }
 	    if (vpix->pending_present) {
-		if (ms->only_hw_presents)
+		if (vpix->scanout_hw)
 		    (void) vmwgfx_scanout_update(ms->fd, vpix->fb_id,
 						 vpix->pending_present);
 		else
@@ -1071,7 +1079,8 @@ drv_screen_init(SCREEN_INIT_ARGS_DECL)
     if (!vmwgfx_saa_init(pScreen, ms->fd, ms->xat, &xorg_flush,
 			 ms->direct_presents,
 			 ms->only_hw_presents,
-			 ms->rendercheck)) {
+			 ms->rendercheck,
+			 ms->has_screen_targets)) {
 	FatalError("Failed to initialize SAA.\n");
     }
 
@@ -1102,9 +1111,14 @@ drv_screen_init(SCREEN_INIT_ARGS_DECL)
     if (ms->xat != NULL) {
 	xf86DrvMsg(pScrn->scrnIndex, ms->from_dp, "Direct presents are %s.\n",
 		   (ms->direct_presents) ? "enabled" : "disabled");
-	xf86DrvMsg(pScrn->scrnIndex, ms->from_hwp, "Hardware only presents "
-		   "are %s.\n",
-		   (ms->only_hw_presents) ? "enabled" : "disabled");
+	if (ms->only_hw_presents)
+	    xf86DrvMsg(pScrn->scrnIndex, ms->from_hwp, "Hardware only presents "
+		       "are enabled.\n");
+	else
+	    xf86DrvMsg(pScrn->scrnIndex, ms->from_hwp, "Hardware only presents "
+		       "are %s.\n",
+		       (ms->has_screen_targets) ? "automatic per scanout" :
+		       "disabled");
     }
 
     xf86SetBackingStore(pScreen);