2022-12-13 16:21:29

by Robert Foss

Subject: [PATCH v1] drm/bridge: lt9611: Fix PLL being unable to lock

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 <[email protected]>
Signed-off-by: Robert Foss <[email protected]>
---
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

2022-12-13 16:54:57

by Amit Pundir

Subject: Re: [PATCH v1] drm/bridge: lt9611: Fix PLL being unable to lock

On Tue, 13 Dec 2022 at 20:33, Robert Foss <[email protected]> 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: <[email protected]> [v5.10+]
Reviewed-by: Amit Pundir <[email protected]>

> Suggested-by: Amit Pundir <[email protected]>
> Signed-off-by: Robert Foss <[email protected]>
> ---
> 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
>

2022-12-15 11:17:30

by Robert Foss

Subject: Re: [PATCH v1] drm/bridge: lt9611: Fix PLL being unable to lock

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