hi, Sasha,

+       if (var->vmode & FB_VMODE_ODD_FLD_FIRST) /* PAL */
+               sig_cfg.odd_field_first = 1;
+       if (var->sync & FB_SYNC_EXT)
+               sig_cfg.ext_clk = 1;
+       if (var->sync & FB_SYNC_HOR_HIGH_ACT)
+               sig_cfg.Hsync_pol = 1;

Please remove FB_SYNC_EXT support.

+static void imx_ipu_fb_disable_overlay(struct fb_info *ovl)
+{
+       struct imx_ipu_fb_info *mxc_ovl = ovl->par;
+
+       if (!mxc_ovl->enabled)
+               return;
+
+       ipu_dp_disable_fg(mxc_ovl->dp);
+       ipu_wait_for_interrupt(451, 100);
+       ipu_idmac_disable_channel(mxc_ovl->ipu_ch);
+       ipu_dmfc_disable_channel(mxc_ovl->dmfc);
+       mxc_ovl->enabled = 0;
+}
Had better has a definition of ipu irq 451.

Jason Chen
BRs