[PATCH] 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>
---
Made the commit message more verbose on Emil's request.

 hw/xfree86/drivers/modesetting/drmmode_display.c | 47 ++++++++++--------------
 1 file changed, 20 insertions(+), 27 deletions(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 0d34ca1..36c3093 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -485,44 +485,36 @@ drmmode_set_cursor_position(xf86CrtcPtr crtc, int x, int y)
     drmModeMoveCursor(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id, x, y);
 }
 
-static void
+static Bool
 drmmode_set_cursor(xf86CrtcPtr crtc)
 {
     drmmode_crtc_private_ptr drmmode_crtc = crtc->driver_private;
     drmmode_ptr drmmode = drmmode_crtc->drmmode;
     uint32_t handle = drmmode_crtc->cursor_bo->handle;
     modesettingPtr ms = modesettingPTR(crtc->scrn);
-    static Bool use_set_cursor2 = TRUE;
     int ret;
 
-    if (use_set_cursor2) {
-        xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(crtc->scrn);
-        CursorPtr cursor = xf86_config->cursor;
-
-        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;
-        if (ret == -EINVAL)
-            use_set_cursor2 = FALSE;
-    }
+    xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(crtc->scrn);
+    CursorPtr cursor = xf86_config->cursor;
 
-    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 */
-    }
+    if (ret)
+        return FALSE; /* fallback to swcursor */
+    return TRUE;
 }
 
-static void
+static Bool
 drmmode_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image)
 {
     modesettingPtr ms = modesettingPTR(crtc->scrn);
@@ -537,7 +529,8 @@ drmmode_load_cursor_argb(xf86CrtcPtr crtc, CARD32 *image)
         ptr[i] = image[i];      // cpu_to_le32(image[i]);
 
     if (drmmode_crtc->cursor_up)
-        drmmode_set_cursor(crtc);
+        return drmmode_set_cursor(crtc);
+    return TRUE;
 }
 
 static void
@@ -799,7 +792,7 @@ static const xf86CrtcFuncsRec drmmode_crtc_funcs = {
     .set_cursor_position = drmmode_set_cursor_position,
     .show_cursor = drmmode_show_cursor,
     .hide_cursor = drmmode_hide_cursor,
-    .load_cursor_argb = drmmode_load_cursor_argb,
+    .load_cursor_argb_check = drmmode_load_cursor_argb,
 
     .gamma_set = drmmode_crtc_gamma_set,
     .destroy = NULL,            /* XXX */
-- 
2.5.0