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>
Signed-off-by: Robert Foss <robert.foss@linaro.org>
---
 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

On Tue, 13 Dec 2022 16:03:04 +0100, Robert Foss 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.
> 
> [...]

Applied, thanks!

Repo: https://cgit.freedesktop.org/drm/drm-misc/


[1/1] drm/bridge: lt9611: Fix PLL being unable to lock
      commit: 2a9df204be0bbb896e087f00b9ee3fc559d5a608



rob

On Tue, 13 Dec 2022 at 20:33, Robert Foss <robert.foss@linaro.org> 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@vger.kernel.org>    [v5.10+]
Reviewed-by: Amit Pundir <amit.pundir@linaro.org>

> Suggested-by: Amit Pundir <amit.pundir@linaro.org>
> Signed-off-by: Robert Foss <robert.foss@linaro.org>
> ---
>  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
>