On both my A13-OLinuxIno and my A13-OLinuxIno-Micro, the vga output gives an unstable image when active low v or hsync is used, so when an external vga dac is used force v and hsync active high independent of what the modeline says.
This fixes the unstable image.
Signed-off-by: Hans de Goede hdegoede@redhat.com --- drivers/video/sunxi_display.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/video/sunxi_display.c b/drivers/video/sunxi_display.c index af728b5..6b8845f 100644 --- a/drivers/video/sunxi_display.c +++ b/drivers/video/sunxi_display.c @@ -645,7 +645,8 @@ static int sunxi_lcdc_get_clk_delay(const struct ctfb_res_modes *mode) return (delay > 30) ? 30 : delay; }
-static void sunxi_lcdc_tcon0_mode_set(const struct ctfb_res_modes *mode) +static void sunxi_lcdc_tcon0_mode_set(const struct ctfb_res_modes *mode, + bool for_ext_vga_dac) { struct sunxi_lcdc_reg * const lcdc = (struct sunxi_lcdc_reg *)SUNXI_LCD0_BASE; @@ -719,6 +720,11 @@ static void sunxi_lcdc_tcon0_mode_set(const struct ctfb_res_modes *mode) val |= SUNXI_LCDC_TCON_HSYNC_MASK; if (!(mode->sync & FB_SYNC_VERT_HIGH_ACT)) val |= SUNXI_LCDC_TCON_VSYNC_MASK; + + /* Some dacs do not work well with active low, so force syncs high */ + if (for_ext_vga_dac) + val = 0; + writel(val, &lcdc->tcon0_io_polarity);
writel(0, &lcdc->tcon0_io_tristate); @@ -1015,7 +1021,7 @@ static void sunxi_mode_set(const struct ctfb_res_modes *mode, hitachi_tx18d42vm_init(); } sunxi_composer_mode_set(mode, address); - sunxi_lcdc_tcon0_mode_set(mode); + sunxi_lcdc_tcon0_mode_set(mode, false); sunxi_composer_enable(); sunxi_lcdc_enable(); #ifdef CONFIG_VIDEO_LCD_SSD2828 @@ -1033,7 +1039,7 @@ static void sunxi_mode_set(const struct ctfb_res_modes *mode, sunxi_vga_enable(); #elif defined CONFIG_VIDEO_VGA_VIA_LCD sunxi_composer_mode_set(mode, address); - sunxi_lcdc_tcon0_mode_set(mode); + sunxi_lcdc_tcon0_mode_set(mode, true); sunxi_composer_enable(); sunxi_lcdc_enable(); sunxi_vga_external_dac_enable();