* configure panel (24bpp, vsync-, hsync-, DP-A protocol, complete
         * raster, associate with display controller)
         */
-       value = SOR_STATE_ASY_VSYNCPOL |
-               SOR_STATE_ASY_HSYNCPOL |
-               SOR_STATE_ASY_PROTOCOL_DP_A |
+       value = SOR_STATE_ASY_PROTOCOL_DP_A |
                SOR_STATE_ASY_CRC_MODE_COMPLETE |
                SOR_STATE_ASY_OWNER(dc->pipe + 1);
 
+       if (mode->flags & DRM_MODE_FLAG_PHSYNC)
+               value &= ~SOR_STATE_ASY_HSYNCPOL;
+
+       if (mode->flags & DRM_MODE_FLAG_NHSYNC)
+               value |= SOR_STATE_ASY_HSYNCPOL;
+
+       if (mode->flags & DRM_MODE_FLAG_PVSYNC)
+               value &= ~SOR_STATE_ASY_VSYNCPOL;
+
+       if (mode->flags & DRM_MODE_FLAG_NVSYNC)
+               value |= SOR_STATE_ASY_VSYNCPOL;
+
        switch (config.bits_per_pixel) {
        case 24:
                value |= SOR_STATE_ASY_PIXELDEPTH_BPP_24_444;