[PATCH xserver] modesetting: allow switching from software to hardware cursors.

[Michael Thayer]

Currently if modesetting ever fails to set a hardware cursor it will switch
to using a software cursor and never go back.  Change this to try a hardware
cursor first every time a new one is set.  This is needed because hardware
may be able to handle some cursors in harware and others not, or virtual
hardware may be able to handle hardware cursors at some times and not others.

Signed-off-by: Michael Thayer <michael.thayer at oracle.com>
---
Checked the current git source and this change is still needed.  This is an
updated patch which takes into account changes in the driver source since
the original patch was created.  Note that other than building I have not
had a chance to test that the updated patch still works, but the difference
against the original is pretty minimal.

 hw/xfree86/drivers/modesetting/drmmode_display.c | 36 +++++++++---------------
 hw/xfree86/drivers/modesetting/drmmode_display.h |  1 -
 2 files changed, 13 insertions(+), 24 deletions(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 6b933e4..ad39f76 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -756,33 +756,23 @@ drmmode_set_cursor(xf86CrtcPtr crtc)
     drmmode_ptr drmmode = drmmode_crtc->drmmode;
     uint32_t handle = drmmode_crtc->cursor_bo->handle;
     modesettingPtr ms = modesettingPTR(crtc->scrn);
+    CursorPtr cursor = xf86CurrentCursor(crtc->scrn->pScreen);
     int ret;
 
-    if (!drmmode_crtc->set_cursor2_failed) {
-        CursorPtr cursor = xf86CurrentCursor(crtc->scrn->pScreen);
-
-        ret =
-            drmModeSetCursor2(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id,
-                              handle, ms->cursor_width, ms->cursor_height,
-                              cursor->bits->xhot, cursor->bits->yhot);
-        if (!ret)
-            return TRUE;
-
-        drmmode_crtc->set_cursor2_failed = TRUE;
-    }
-
-    ret = drmModeSetCursor(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id, handle,
-                           ms->cursor_width, ms->cursor_height);
+    ret =
+        drmModeSetCursor2(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id,
+                          handle, ms->cursor_width, ms->cursor_height,
+                          cursor->bits->xhot, cursor->bits->yhot);
+    if (!ret)
+        return TRUE;
 
-    if (ret) {
-        xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(crtc->scrn);
-        xf86CursorInfoPtr cursor_info = xf86_config->cursor_info;
+    /* -EINVAL can mean bad cursor parameters or Cursor2 API not supported. */
+    if (ret == -EINVAL)
+        ret = drmModeSetCursor(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id, handle,
+                               ms->cursor_width, ms->cursor_height);
 
-        cursor_info->MaxWidth = cursor_info->MaxHeight = 0;
-        drmmode_crtc->drmmode->sw_cursor = TRUE;
-        /* fallback to swcursor */
-        return FALSE;
-    }
+    if (ret)
+        return FALSE; /* fallback to swcursor */
     return TRUE;
 }
 
diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.h b/hw/xfree86/drivers/modesetting/drmmode_display.h
index 50976b8..5170bf5 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.h
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.h
@@ -92,7 +92,6 @@ typedef struct {
     int dpms_mode;
     struct dumb_bo *cursor_bo;
     Bool cursor_up;
-    Bool set_cursor2_failed;
     Bool first_cursor_load_done;
     uint16_t lut_r[256], lut_g[256], lut_b[256];
 
-- 
2.9.3