From: Robert Foss <robert.foss@xxxxxxxxxx> commit 2a9df204be0bbb896e087f00b9ee3fc559d5a608 upstream. This fixes PLL being unable to lock, and is derived from an equivalent downstream commit. Available LT9611 documentation does not list this register, neither does LT9611UXC (which is a different chip). This commit has been confirmed to fix HDMI output on DragonBoard 845c. Suggested-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Reviewed-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20221213150304.4189760-1-robert.foss@xxxxxxxxxx Signed-off-by: Amit Pundir <amit.pundir@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/gpu/drm/bridge/lontium-lt9611.c | 1 + 1 file changed, 1 insertion(+) --- a/drivers/gpu/drm/bridge/lontium-lt9611.c +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c @@ -256,6 +256,7 @@ static int lt9611_pll_setup(struct lt961 { 0x8126, 0x55 }, { 0x8127, 0x66 }, { 0x8128, 0x88 }, + { 0x812a, 0x20 }, }; regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));
