This is the logical place to put the backlight device, and it also
fixes a kernel crash if the MIPI host is removed. Previously the
backlight device would be unregistered twice when this happened - once
as a child of the MIPI host through `mipi_dsi_host_unregister`, and
once when the panel device is destroyed.

Fixes: 12a6cbd4f3f1 ("drm/panel: otm8009a: Use new backlight API")
Signed-off-by: James Cowgill <james.cowgill@blaize.com>
Cc: stable@vger.kernel.org
---
 drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
index b4729a94c34a8..898b892f11439 100644
--- a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
+++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
@@ -471,7 +471,7 @@ static int otm8009a_probe(struct mipi_dsi_device *dsi)
 		       DRM_MODE_CONNECTOR_DSI);
 
 	ctx->bl_dev = devm_backlight_device_register(dev, dev_name(dev),
-						     dsi->host->dev, ctx,
+						     dev, ctx,
 						     &otm8009a_backlight_ops,
 						     NULL);
 	if (IS_ERR(ctx->bl_dev)) {
-- 
2.39.1

Hi,

On Wed, 12 Apr 2023 17:35:07 +0000, James Cowgill wrote:
> This is the logical place to put the backlight device, and it also
> fixes a kernel crash if the MIPI host is removed. Previously the
> backlight device would be unregistered twice when this happened - once
> as a child of the MIPI host through `mipi_dsi_host_unregister`, and
> once when the panel device is destroyed.
> 
> 
> [...]

Thanks, Applied to https://anongit.freedesktop.org/git/drm/drm-misc.git (drm-misc-next-fixes)

[1/1] drm/panel: otm8009a: Set backlight parent to panel device
      https://cgit.freedesktop.org/drm/drm-misc/commit/?id=ab4f869fba6119997f7630d600049762a2b014fa

-- 
Neil

On 12/04/2023 19:35, James Cowgill wrote:
> This is the logical place to put the backlight device, and it also
> fixes a kernel crash if the MIPI host is removed. Previously the
> backlight device would be unregistered twice when this happened - once
> as a child of the MIPI host through `mipi_dsi_host_unregister`, and
> once when the panel device is destroyed.
> 
> Fixes: 12a6cbd4f3f1 ("drm/panel: otm8009a: Use new backlight API")
> Signed-off-by: James Cowgill <james.cowgill@blaize.com>
> Cc: stable@vger.kernel.org
> ---
>   drivers/gpu/drm/panel/panel-orisetech-otm8009a.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> index b4729a94c34a8..898b892f11439 100644
> --- a/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> +++ b/drivers/gpu/drm/panel/panel-orisetech-otm8009a.c
> @@ -471,7 +471,7 @@ static int otm8009a_probe(struct mipi_dsi_device *dsi)
>   		       DRM_MODE_CONNECTOR_DSI);
>   
>   	ctx->bl_dev = devm_backlight_device_register(dev, dev_name(dev),
> -						     dsi->host->dev, ctx,
> +						     dev, ctx,
>   						     &otm8009a_backlight_ops,
>   						     NULL);
>   	if (IS_ERR(ctx->bl_dev)) {

Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>