On Tue, 13 Dec 2022 at 20:33, Robert Foss <robert.foss@xxxxxxxxxx> wrote:
>
> 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.
>
Cc: <stable@xxxxxxxxxxxxxxx> [v5.10+]
Reviewed-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> Suggested-by: Amit Pundir <amit.pundir@xxxxxxxxxx>
> Signed-off-by: Robert Foss <robert.foss@xxxxxxxxxx>
> ---
> 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 ffcdc8dba3798..3ce4e495aee50 100644
> --- a/drivers/gpu/drm/bridge/lontium-lt9611.c
> +++ b/drivers/gpu/drm/bridge/lontium-lt9611.c
> @@ -259,6 +259,7 @@ 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));
> --
> 2.34.1
>
