diff mbox series

[PATCHv3] drm/i915/display: add support for dual panel backlight

Message ID 20220803080823.2952635-1-arun.r.murthy@intel.com (mailing list archive)
State New, archived
Headers show
Series [PATCHv3] drm/i915/display: add support for dual panel backlight | expand

Commit Message

Murthy, Arun R Aug. 3, 2022, 8:08 a.m. UTC
The patch with commit 20f85ef89d94 ("drm/i915/backlight: use unique
backlight device names") already adds support for dual panel backlight
but with error prints. Since the patch tried to create the backlight
device with the same name and upon failure will try with a different
name it leads to failure logs in dmesg inturn getting caught by CI.

This patch alternately will check if the backlight class of same name
exists, will use a different name.

v2: reworked on top of the patch 20f85ef89d94 ("drm/i915/backlight: use
unique backlight device names")
v3: fixed the ref count leak(Jani N)

Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
---
 .../gpu/drm/i915/display/intel_backlight.c    | 24 ++++++++-----------
 1 file changed, 10 insertions(+), 14 deletions(-)

Comments

Jani Nikula Aug. 3, 2022, 8:19 a.m. UTC | #1
On Wed, 03 Aug 2022, Arun R Murthy <arun.r.murthy@intel.com> wrote:
> The patch with commit 20f85ef89d94 ("drm/i915/backlight: use unique
> backlight device names") already adds support for dual panel backlight
> but with error prints. Since the patch tried to create the backlight
> device with the same name and upon failure will try with a different
> name it leads to failure logs in dmesg inturn getting caught by CI.
>
> This patch alternately will check if the backlight class of same name
> exists, will use a different name.
>
> v2: reworked on top of the patch 20f85ef89d94 ("drm/i915/backlight: use
> unique backlight device names")
> v3: fixed the ref count leak(Jani N)

Forgot to git add the change? ;)

Please also send as a new patch, not in-reply-to, I think CI gets
confused when it's supposed to be a standalone patch but sent in the
middle of a big thread.

BR,
Jani.

>
> Signed-off-by: Arun R Murthy <arun.r.murthy@intel.com>
> ---
>  .../gpu/drm/i915/display/intel_backlight.c    | 24 ++++++++-----------
>  1 file changed, 10 insertions(+), 14 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c
> index 110fc98ec280..1e550d048e86 100644
> --- a/drivers/gpu/drm/i915/display/intel_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_backlight.c
> @@ -971,26 +971,22 @@ int intel_backlight_device_register(struct intel_connector *connector)
>  	if (!name)
>  		return -ENOMEM;
>  
> -	bd = backlight_device_register(name, connector->base.kdev, connector,
> -				       &intel_backlight_device_ops, &props);
> -
> -	/*
> -	 * Using the same name independent of the drm device or connector
> -	 * prevents registration of multiple backlight devices in the
> -	 * driver. However, we need to use the default name for backward
> -	 * compatibility. Use unique names for subsequent backlight devices as a
> -	 * fallback when the default name already exists.
> -	 */
> -	if (IS_ERR(bd) && PTR_ERR(bd) == -EEXIST) {
> +	if (backlight_device_get_by_name(name)) {
> +		/*
> +		 * Using the same name independent of the drm device or connector
> +		 * prevents registration of multiple backlight devices in the
> +		 * driver. However, we need to use the default name for backward
> +		 * compatibility. Use unique names for subsequent backlight devices as a
> +		 * fallback when the default name already exists.
> +		 */
>  		kfree(name);
>  		name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
>  				 i915->drm.primary->index, connector->base.name);
>  		if (!name)
>  			return -ENOMEM;
> -
> -		bd = backlight_device_register(name, connector->base.kdev, connector,
> -					       &intel_backlight_device_ops, &props);
>  	}
> +	bd = backlight_device_register(name, connector->base.kdev, connector,
> +				       &intel_backlight_device_ops, &props);
>  
>  	if (IS_ERR(bd)) {
>  		drm_err(&i915->drm,
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/intel_backlight.c b/drivers/gpu/drm/i915/display/intel_backlight.c
index 110fc98ec280..1e550d048e86 100644
--- a/drivers/gpu/drm/i915/display/intel_backlight.c
+++ b/drivers/gpu/drm/i915/display/intel_backlight.c
@@ -971,26 +971,22 @@  int intel_backlight_device_register(struct intel_connector *connector)
 	if (!name)
 		return -ENOMEM;
 
-	bd = backlight_device_register(name, connector->base.kdev, connector,
-				       &intel_backlight_device_ops, &props);
-
-	/*
-	 * Using the same name independent of the drm device or connector
-	 * prevents registration of multiple backlight devices in the
-	 * driver. However, we need to use the default name for backward
-	 * compatibility. Use unique names for subsequent backlight devices as a
-	 * fallback when the default name already exists.
-	 */
-	if (IS_ERR(bd) && PTR_ERR(bd) == -EEXIST) {
+	if (backlight_device_get_by_name(name)) {
+		/*
+		 * Using the same name independent of the drm device or connector
+		 * prevents registration of multiple backlight devices in the
+		 * driver. However, we need to use the default name for backward
+		 * compatibility. Use unique names for subsequent backlight devices as a
+		 * fallback when the default name already exists.
+		 */
 		kfree(name);
 		name = kasprintf(GFP_KERNEL, "card%d-%s-backlight",
 				 i915->drm.primary->index, connector->base.name);
 		if (!name)
 			return -ENOMEM;
-
-		bd = backlight_device_register(name, connector->base.kdev, connector,
-					       &intel_backlight_device_ops, &props);
 	}
+	bd = backlight_device_register(name, connector->base.kdev, connector,
+				       &intel_backlight_device_ops, &props);
 
 	if (IS_ERR(bd)) {
 		drm_err(&i915->drm,