thr3ads.net - Nouveau - [PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace [Apr 2024]

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Angelo Dureghello

2024-Apr-12 19:49 UTC

[PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace

Add working backlight for "ada lovelace" missing case.

The nvif method is actually not working for this chipset so
used the drm apis. Also, by dpcd, drm layer is calculating a
max brightness of 255, but to get a real correct max brightnes
the maximum must be multiplied by a factor of 16.

Tested to work properly in Legion Lenovo Pro 5

Lenovo Legion 5 Pro 16ARX8
Bios ver LPCN49WW
	 LPEC49WW
SN PF4T63AZ
Nvidia RTX4060 MaxQ/Mobile rev a1 (ADA LOVELACE AD107M)
AMD Ryzen 9 7945HX + Radeon

and wayland.

---
Changes for v2:
- add some comments
- remove x16 multiplication (hack)
- remove forgot debug printk

Signed-off-by: Angelo Dureghello <angelo at kernel-space.org>
---
 drivers/gpu/drm/nouveau/nouveau_backlight.c | 54 +++++++++++++++++++++
 1 file changed, 54 insertions(+)

diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c
b/drivers/gpu/drm/nouveau/nouveau_backlight.c
index d47442125fa1..7b7306d18ad7 100644
--- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
+++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
@@ -286,6 +286,56 @@ nv50_backlight_init(struct nouveau_backlight *bl,
 	return 0;
 }
 
+static int
+nv19x_backlight_init(struct nouveau_backlight *bl,
+		     struct nouveau_connector *nv_conn,
+		     struct nouveau_encoder *nv_encoder,
+		     struct backlight_properties *props,
+		     const struct backlight_ops **ops)
+{
+	int ret;
+	u16 current_level;
+	u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
+	u8 current_mode;
+	struct nouveau_drm *drm = nouveau_drm(nv_encoder->base.base.dev);
+
+	/*
+	 * nvif functions, so also nvif_outp_bl_get, are not working with this
+	 * connector (return -22), using only drm layer.
+	 */
+	if (nv_conn->type == DCB_CONNECTOR_eDP) {
+
+		ret = drm_dp_dpcd_read(&nv_conn->aux, DP_EDP_DPCD_REV, edp_dpcd,
+				       EDP_DISPLAY_CTL_CAP_SIZE);
+		if (ret < 0)
+			return ret;
+		if (!drm_edp_backlight_supported(edp_dpcd))
+			return -ENODEV;
+
+		ret = drm_edp_backlight_init(&nv_conn->aux, &bl->edp_info, 0,
edp_dpcd,
+					 &current_level, &current_mode);
+		if (ret < 0)
+			return ret;
+
+		ret = drm_edp_backlight_enable(&nv_conn->aux, &bl->edp_info,
current_level);
+		if (ret < 0) {
+			NV_ERROR(drm, "Failed to enable backlight on %s: %d\n",
+				 nv_conn->base.name, ret);
+			return ret;
+		}
+
+		*ops = &nv50_edp_bl_ops;
+
+		props->max_brightness = bl->edp_info.max;
+		props->brightness = current_level;
+		bl->uses_dpcd = true;
+
+		return 0;
+	}
+
+	return -ENODEV;
+}
+
 int
 nouveau_backlight_init(struct drm_connector *connector)
 {
@@ -332,6 +382,10 @@ nouveau_backlight_init(struct drm_connector *connector)
 		ret = nv50_backlight_init(bl, nouveau_connector(connector),
 					  nv_encoder, &props, &ops);
 		break;
+	case NV_DEVICE_INFO_V0_ADA:
+		ret = nv19x_backlight_init(bl, nouveau_connector(connector),
+					   nv_encoder, &props, &ops);
+		break;
 	default:
 		ret = 0;
 		goto fail_alloc;
-- 
2.44.0

Angelo Dureghello

2024-Apr-12 19:49 UTC

head link

[PATCH v2 2/2] drm/dp: set pwm bit count when pwm hz is not set

Set pwmgen_bit_count to have proper brightness inc/dec steps
even when driver_pwm_freq_hz (optional) is zero.

cat /sys/class/backlight/nv_backlight/max_brightness
255

Can now tune properly backlight from 0 to 255.

---
Changes for v2:
none

Signed-off-by: Angelo Dureghello <angelo at kernel-space.org>
---
 drivers/gpu/drm/display/drm_dp_helper.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/display/drm_dp_helper.c
b/drivers/gpu/drm/display/drm_dp_helper.c
index f5d4be897866..30c4ed0f2ff1 100644
--- a/drivers/gpu/drm/display/drm_dp_helper.c
+++ b/drivers/gpu/drm/display/drm_dp_helper.c
@@ -3768,6 +3768,7 @@ drm_edp_backlight_probe_max(struct drm_dp_aux *aux, struct
drm_edp_backlight_inf
 	}
 
 	pn &= DP_EDP_PWMGEN_BIT_COUNT_MASK;
+	bl->pwmgen_bit_count = pn;
 	bl->max = (1 << pn) - 1;
 	if (!driver_pwm_freq_hz)
 		return 0;
-- 
2.44.0

Lyude Paul

2024-Apr-15 16:54 UTC

head link

[PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace

Hm. Could you share some logs with drm.debug=0x116? I'm a bit confused
because I would have thought that we were already probing for eDP
backlights seeing as I added support for them at one point?

(I hope this isn't the point I learn I actually forgot to add support
for them :P)


On Fri, 2024-04-12 at 21:49 +0200, Angelo Dureghello
wrote:> Add working backlight for "ada lovelace" missing case.
> 
> The nvif method is actually not working for this chipset so
> used the drm apis. Also, by dpcd, drm layer is calculating a
> max brightness of 255, but to get a real correct max brightnes
> the maximum must be multiplied by a factor of 16.
> 
> Tested to work properly in Legion Lenovo Pro 5
> 
> Lenovo Legion 5 Pro 16ARX8
> Bios ver LPCN49WW
> 	 LPEC49WW
> SN PF4T63AZ
> Nvidia RTX4060 MaxQ/Mobile rev a1 (ADA LOVELACE AD107M)
> AMD Ryzen 9 7945HX + Radeon
> 
> and wayland.
> 
> ---
> Changes for v2:
> - add some comments
> - remove x16 multiplication (hack)
> - remove forgot debug printk
> 
> Signed-off-by: Angelo Dureghello <angelo at kernel-space.org>
> ---
> ?drivers/gpu/drm/nouveau/nouveau_backlight.c | 54
> +++++++++++++++++++++
> ?1 file changed, 54 insertions(+)
> 
> diff --git a/drivers/gpu/drm/nouveau/nouveau_backlight.c
> b/drivers/gpu/drm/nouveau/nouveau_backlight.c
> index d47442125fa1..7b7306d18ad7 100644
> --- a/drivers/gpu/drm/nouveau/nouveau_backlight.c
> +++ b/drivers/gpu/drm/nouveau/nouveau_backlight.c
> @@ -286,6 +286,56 @@ nv50_backlight_init(struct nouveau_backlight
> *bl,
> ?	return 0;
> ?}
> ?
> +static int
> +nv19x_backlight_init(struct nouveau_backlight *bl,
> +		???? struct nouveau_connector *nv_conn,
> +		???? struct nouveau_encoder *nv_encoder,
> +		???? struct backlight_properties *props,
> +		???? const struct backlight_ops **ops)
> +{
> +	int ret;
> +	u16 current_level;
> +	u8 edp_dpcd[EDP_DISPLAY_CTL_CAP_SIZE];
> +	u8 current_mode;
> +	struct nouveau_drm *drm = nouveau_drm(nv_encoder-
> >base.base.dev);
> +
> +	/*
> +	 * nvif functions, so also nvif_outp_bl_get, are not working
> with this
> +	 * connector (return -22), using only drm layer.
> +	 */
> +	if (nv_conn->type == DCB_CONNECTOR_eDP) {
> +
> +		ret = drm_dp_dpcd_read(&nv_conn->aux,
> DP_EDP_DPCD_REV, edp_dpcd,
> +				?????? EDP_DISPLAY_CTL_CAP_SIZE);
> +		if (ret < 0)
> +			return ret;
> +		if (!drm_edp_backlight_supported(edp_dpcd))
> +			return -ENODEV;
> +
> +		ret = drm_edp_backlight_init(&nv_conn->aux, &bl-
> >edp_info, 0, edp_dpcd,
> +					 &current_level,
> &current_mode);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = drm_edp_backlight_enable(&nv_conn->aux, &bl-
> >edp_info, current_level);
> +		if (ret < 0) {
> +			NV_ERROR(drm, "Failed to enable backlight on
> %s: %d\n",
> +				 nv_conn->base.name, ret);
> +			return ret;
> +		}
> +
> +		*ops = &nv50_edp_bl_ops;
> +
> +		props->max_brightness = bl->edp_info.max;
> +		props->brightness = current_level;
> +		bl->uses_dpcd = true;
> +
> +		return 0;
> +	}
> +
> +	return -ENODEV;
> +}
> +
> ?int
> ?nouveau_backlight_init(struct drm_connector *connector)
> ?{
> @@ -332,6 +382,10 @@ nouveau_backlight_init(struct drm_connector
> *connector)
> ?		ret = nv50_backlight_init(bl,
> nouveau_connector(connector),
> ?					? nv_encoder, &props, &ops);
> ?		break;
> +	case NV_DEVICE_INFO_V0_ADA:
> +		ret = nv19x_backlight_init(bl,
> nouveau_connector(connector),
> +					?? nv_encoder, &props,
> &ops);
> +		break;
> ?	default:
> ?		ret = 0;
> ?		goto fail_alloc;
-- 
Cheers,
 Lyude Paul (she/her)
 Software Engineer at Red Hat

Nouveau - Apr 2024 - [PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace

[PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace

[PATCH v2 2/2] drm/dp: set pwm bit count when pwm hz is not set

[PATCH v2 1/2] drm/nouveau/disp: add backlight for ada lovelace