drm/radeon: fix doublescan modes (v2)

commit fd99a094 upstream.

Use the correct flags for atom.

v2: handle DRM_MODE_FLAG_DBLCLK
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

drivers/gpu/drm/radeon/atombios_crtc.c

@@ -302,8 +302,10 @@ atombios_set_crtc_dtd_timing(struct drm_crtc *crtc,
 		misc |= ATOM_COMPOSITESYNC;
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		misc |= ATOM_INTERLACE;
-	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		misc |= ATOM_DOUBLE_CLOCK_MODE;
+	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+		misc |= ATOM_H_REPLICATIONBY2 | ATOM_V_REPLICATIONBY2;
 
 	args.susModeMiscInfo.usAccess = cpu_to_le16(misc);
 	args.ucCRTC = radeon_crtc->crtc_id;
@@ -346,8 +348,10 @@ static void atombios_crtc_set_timing(struct drm_crtc *crtc,
 		misc |= ATOM_COMPOSITESYNC;
 	if (mode->flags & DRM_MODE_FLAG_INTERLACE)
 		misc |= ATOM_INTERLACE;
-	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+	if (mode->flags & DRM_MODE_FLAG_DBLCLK)
 		misc |= ATOM_DOUBLE_CLOCK_MODE;
+	if (mode->flags & DRM_MODE_FLAG_DBLSCAN)
+		misc |= ATOM_H_REPLICATIONBY2 | ATOM_V_REPLICATIONBY2;
 
 	args.susModeMiscInfo.usAccess = cpu_to_le16(misc);
 	args.ucCRTC = radeon_crtc->crtc_id;