From: Robert Foss robert.foss@linaro.org

[ Upstream commit 2a9df204be0bbb896e087f00b9ee3fc559d5a608 ]

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@linaro.org Reviewed-by: Amit Pundir amit.pundir@linaro.org Signed-off-by: Robert Foss robert.foss@linaro.org Link: https://patchwork.freedesktop.org/patch/msgid/20221213150304.4189760-1-rober... Signed-off-by: Amit Pundir amit.pundir@linaro.org ---

To be cherry-picked on v5.10.y, v5.15.y and v6.1.y.

drivers/gpu/drm/bridge/lontium-lt9611.c | 1 + 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/bridge/lontium-lt9611.c b/drivers/gpu/drm/bridge/lontium-lt9611.c index 3b77238ca4af..ae8c6d9d4095 100644 --- a/drivers/gpu/drm/bridge/lontium-lt9611.c +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c @@ -258,6 +258,7 @@ static int lt9611_pll_setup(struct lt9611 *lt9611, const struct drm_display_mode { 0x8126, 0x55 }, { 0x8127, 0x66 }, { 0x8128, 0x88 }, + { 0x812a, 0x20 }, };

regmap_multi_reg_write(lt9611->regmap, reg_cfg, ARRAY_SIZE(reg_cfg));