2022-02-07 17:54:59

by Lyude Paul

Subject: [PATCH] drm/nouveau/backlight: Just set all backlight types as RAW

Currently we can get a warning on systems with eDP backlights like so:

nv_backlight: invalid backlight type
WARNING: CPU: 4 PID: 454 at drivers/video/backlight/backlight.c:420
backlight_device_register+0x226/0x250

This happens as a result of us not filling out props.type for the eDP
backlight, even though we do it for all other backlight types.

Since nothing in our driver uses anything but BACKLIGHT_RAW, let's take the
props\.type assignments out of the codepaths for individual backlight types
and just set it unconditionally to prevent this from happening again.

Signed-off-by: Lyude Paul <[email protected]>
Fixes: 6eca310e8924 ("drm/nouveau/kms/nv50-: Add basic DPCD backlight support for nouveau")
Cc: <[email protected]> # v5.15+
---
drivers/gpu/drm/nouveau/nouveau_backlight.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index 6af12dc99d7f..daf9f87477ba 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -101,7 +101,6 @@ nv40_backlight_init(struct nouveau_encoder *encoder,
if (!(nvif_rd32(device, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
return -ENODEV;

- props->type = BACKLIGHT_RAW;
props->max_brightness = 31;
*ops = &nv40_bl_ops;
return 0;
@@ -343,7 +342,6 @@ nv50_backlight_init(struct nouveau_backlight *bl,
else
*ops = &nva3_bl_ops;

- props->type = BACKLIGHT_RAW;
props->max_brightness = 100;

return 0;
@@ -411,6 +409,7 @@ nouveau_backlight_init(struct drm_connector *connector)
goto fail_alloc;
}

+ props.type = BACKLIGHT_RAW;
bl->dev = backlight_device_register(backlight_name, connector->kdev,
nv_encoder, ops, &props);
if (IS_ERR(bl->dev)) {
--
2.34.1

2022-02-09 07:01:33

by Karol Herbst

Subject: Re: [PATCH] drm/nouveau/backlight: Just set all backlight types as RAW

Reviewed-by: Karol Herbst <[email protected]>

On Fri, Feb 4, 2022 at 8:33 PM Lyude Paul <[email protected]> wrote:
>
> Currently we can get a warning on systems with eDP backlights like so:
>
> nv_backlight: invalid backlight type
> WARNING: CPU: 4 PID: 454 at drivers/video/backlight/backlight.c:420
> backlight_device_register+0x226/0x250
>
> This happens as a result of us not filling out props.type for the eDP
> backlight, even though we do it for all other backlight types.
>
> Since nothing in our driver uses anything but BACKLIGHT_RAW, let's take the
> props\.type assignments out of the codepaths for individual backlight types
> and just set it unconditionally to prevent this from happening again.
>
> Signed-off-by: Lyude Paul <[email protected]>
> Fixes: 6eca310e8924 ("drm/nouveau/kms/nv50-: Add basic DPCD backlight support for nouveau")
> Cc: <[email protected]> # v5.15+
> ---
> drivers/gpu/drm/nouveau/nouveau_backlight.c | 3 +--
> 1 file changed, 1 insertion(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c b/drivers/gpu/drm/nouveau/nouveau_backlight.c
> index 6af12dc99d7f..daf9f87477ba 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
> @@ -101,7 +101,6 @@ nv40_backlight_init(struct nouveau_encoder *encoder,
> if (!(nvif_rd32(device, NV40_PMC_BACKLIGHT) & NV40_PMC_BACKLIGHT_MASK))
> return -ENODEV;
>
> - props->type = BACKLIGHT_RAW;
> props->max_brightness = 31;
> *ops = &nv40_bl_ops;
> return 0;
> @@ -343,7 +342,6 @@ nv50_backlight_init(struct nouveau_backlight *bl,
> else
> *ops = &nva3_bl_ops;
>
> - props->type = BACKLIGHT_RAW;
> props->max_brightness = 100;
>
> return 0;
> @@ -411,6 +409,7 @@ nouveau_backlight_init(struct drm_connector *connector)
> goto fail_alloc;
> }
>
> + props.type = BACKLIGHT_RAW;
> bl->dev = backlight_device_register(backlight_name, connector->kdev,
> nv_encoder, ops, &props);
> if (IS_ERR(bl->dev)) {
> --
> 2.34.1
>