drm/nv04-nv40: Fall back to panel rescaling if we have no usable native mode.

This allows the user to set a mode larger than the native one, useful
if we had trouble finding the actual native mode (e.g. because it goes
above the hardware bandwidth limits).

Reported-by: Grzesiek Sójka <pld@pfu.pl>
Signed-off-by: Francisco Jerez <currojerez@riseup.net>
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/drivers/gpu/drm/nouveau/nv04_dfp.c b/drivers/gpu/drm/nouveau/nv04_dfp.c
index c936403b26e2..ef23550407b5 100644
--- a/drivers/gpu/drm/nouveau/nv04_dfp.c
+++ b/drivers/gpu/drm/nouveau/nv04_dfp.c
@@ -185,14 +185,15 @@ static bool nv04_dfp_mode_fixup(struct drm_encoder *encoder,
         struct nouveau_encoder *nv_encoder = nouveau_encoder(encoder);
         struct nouveau_connector *nv_connector = nouveau_encoder_connector_get(nv_encoder);
 
-        /* For internal panels and gpu scaling on DVI we need the native mode */
-        if (nv_connector->scaling_mode != DRM_MODE_SCALE_NONE) {
-                if (!nv_connector->native_mode)
-                        return false;
+        if (!nv_connector->native_mode ||
+            nv_connector->scaling_mode == DRM_MODE_SCALE_NONE ||
+            mode->hdisplay > nv_connector->native_mode->hdisplay ||
+            mode->vdisplay > nv_connector->native_mode->vdisplay) {
+                nv_encoder->mode = *adjusted_mode;
+
+        } else {
                 nv_encoder->mode = *nv_connector->native_mode;
                 adjusted_mode->clock = nv_connector->native_mode->clock;
-        } else {
-                nv_encoder->mode = *adjusted_mode;
         }
 
         return true;