[PATCH xserver] modesetting: allow switching from software to hardware cursors (v3).

[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.

Changes since v1 and v2:
 * take into account the switch to load_cursor_argb_check
 * altogether drop the fall-back path to SetCursor() if SetCursor2() fails:
   SetCursor2() has been supported in released kernels for three years now,
   and I think a software cursor fallback is acceptable if anyone has to use
   1.19 with such an old kernel
 * drop the special case for loading a cursor sprite when the cursor is
   hidden: we set HARDWARE_CURSOR_UPDATE_UNHIDDEN, so all calls to
   load_cursor will be followed by calls to show_cursor unless the load
   fails (when a call to hide_cursor should follow)

Signed-off-by: Michael Thayer <michael.thayer at oracle.com>
---
I hope that you are happy with the change I made to remove the set_cursor1
fall-back (it does rather simplify the code!); if not I will send v4.

 hw/xfree86/drivers/modesetting/drmmode_display.c | 40 ++++--------------------
 hw/xfree86/drivers/modesetting/drmmode_display.h |  2 --
 2 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.c b/hw/xfree86/drivers/modesetting/drmmode_display.c
index 6b933e4..bf5ca32 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.c
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.c
@@ -756,33 +756,12 @@ drmmode_set_cursor(xf86CrtcPtr crtc)
     drmmode_ptr drmmode = drmmode_crtc->drmmode;
     uint32_t handle = drmmode_crtc->cursor_bo->handle;
     modesettingPtr ms = modesettingPTR(crtc->scrn);
-    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);
+    CursorPtr cursor = xf86CurrentCursor(crtc->scrn->pScreen);
 
-    if (ret) {
-        xf86CrtcConfigPtr xf86_config = XF86_CRTC_CONFIG_PTR(crtc->scrn);
-        xf86CursorInfoPtr cursor_info = xf86_config->cursor_info;
-
-        cursor_info->MaxWidth = cursor_info->MaxHeight = 0;
-        drmmode_crtc->drmmode->sw_cursor = TRUE;
-        /* fallback to swcursor */
-        return FALSE;
-    }
+    if (drmModeSetCursor2(drmmode->fd, drmmode_crtc->mode_crtc->crtc_id,
+                          handle, ms->cursor_width, ms->cursor_height,
+                          cursor->bits->xhot, cursor->bits->yhot))
+        return FALSE; /* fallback to swcursor */
     return TRUE;
 }
 
@@ -809,14 +788,7 @@ drmmode_load_cursor_argb_check(xf86CrtcPtr crtc, CARD32 *image)
     for (i = 0; i < ms->cursor_width * ms->cursor_height; i++)
         ptr[i] = image[i];      // cpu_to_le32(image[i]);
 
-    if (drmmode_crtc->cursor_up || !drmmode_crtc->first_cursor_load_done) {
-        Bool ret = drmmode_set_cursor(crtc);
-        if (!drmmode_crtc->cursor_up)
-            drmmode_hide_cursor(crtc);
-        drmmode_crtc->first_cursor_load_done = TRUE;
-        return ret;
-    }
-    return TRUE;
+    return drmmode_set_cursor(crtc);
 }
 
 static void
diff --git a/hw/xfree86/drivers/modesetting/drmmode_display.h b/hw/xfree86/drivers/modesetting/drmmode_display.h
index 50976b8..f774250 100644
--- a/hw/xfree86/drivers/modesetting/drmmode_display.h
+++ b/hw/xfree86/drivers/modesetting/drmmode_display.h
@@ -92,8 +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];
 
     drmmode_bo rotate_bo;
-- 
2.9.3