[PATCH] drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[PATCH] drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[Arnd Bergmann]

From: Arnd Bergmann <arnd@arndb.de>

Like a number of other panel drivers, this newly merged driver
needs DRM_DISPLAY_DSC_HELPER to be enabled:

arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-himax-hx83121a.o: in function `himax_prepare':
panel-himax-hx83121a.c:(.text+0x1024): undefined reference to `drm_dsc_pps_payload_pack'

Fixes: a7c61963b727 ("drm/panel: Add Himax HX83121A panel driver")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/gpu/drm/panel/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index cc8c8a066bb9..ce6098c0343a 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -208,6 +208,7 @@ config DRM_PANEL_HIMAX_HX83121A
 	depends on OF
 	depends on DRM_MIPI_DSI
 	depends on BACKLIGHT_CLASS_DEVICE
+	select DRM_DISPLAY_DSC_HELPER
 	select DRM_KMS_HELPER
 	help
 	  Say Y here if you want to enable support for Himax HX83121A-based
-- 
2.39.5

Re: [PATCH] drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[Neil Armstrong]

On 4/13/26 09:10, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Like a number of other panel drivers, this newly merged driver
> needs DRM_DISPLAY_DSC_HELPER to be enabled:
> 
> arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-himax-hx83121a.o: in function `himax_prepare':
> panel-himax-hx83121a.c:(.text+0x1024): undefined reference to `drm_dsc_pps_payload_pack'
> 
> Fixes: a7c61963b727 ("drm/panel: Add Himax HX83121A panel driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   drivers/gpu/drm/panel/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index cc8c8a066bb9..ce6098c0343a 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -208,6 +208,7 @@ config DRM_PANEL_HIMAX_HX83121A
>   	depends on OF
>   	depends on DRM_MIPI_DSI
>   	depends on BACKLIGHT_CLASS_DEVICE
> +	select DRM_DISPLAY_DSC_HELPER
>   	select DRM_KMS_HELPER
>   	help
>   	  Say Y here if you want to enable support for Himax HX83121A-based

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

Thanks,
Neil

Re: [PATCH] drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[David Heidelberg]

On 13/04/2026 09:10, Arnd Bergmann wrote:
> From: Arnd Bergmann <arnd@arndb.de>
> 
> Like a number of other panel drivers, this newly merged driver
> needs DRM_DISPLAY_DSC_HELPER to be enabled:
> 
> arm-linux-gnueabi-ld: drivers/gpu/drm/panel/panel-himax-hx83121a.o: in function `himax_prepare':
> panel-himax-hx83121a.c:(.text+0x1024): undefined reference to `drm_dsc_pps_payload_pack'
> 
> Fixes: a7c61963b727 ("drm/panel: Add Himax HX83121A panel driver")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> ---
>   drivers/gpu/drm/panel/Kconfig | 1 +
>   1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index cc8c8a066bb9..ce6098c0343a 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -208,6 +208,7 @@ config DRM_PANEL_HIMAX_HX83121A
>   	depends on OF
>   	depends on DRM_MIPI_DSI
>   	depends on BACKLIGHT_CLASS_DEVICE
> +	select DRM_DISPLAY_DSC_HELPER
>   	select DRM_KMS_HELPER
>   	help
>   	  Say Y here if you want to enable support for Himax HX83121A-based

Reviewed-by: David Heidelberg <david@ixit.cz>

Claude review: drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[Claude Code Review Bot]

Overall Series Review

Subject: drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER
Author: Arnd Bergmann <arnd@kernel.org>
Patches: 3
Reviewed: 2026-04-13T18:44:29.583006

---

This is a single, straightforward build-fix patch from Arnd Bergmann that adds a missing Kconfig dependency for the newly merged Himax HX83121A panel driver. The driver uses `drm_dsc_pps_payload_pack()` from `DRM_DISPLAY_DSC_HELPER` but its Kconfig entry did not `select` that symbol, leading to a linker error when `DRM_DISPLAY_DSC_HELPER` is not otherwise enabled.

The fix follows the exact same pattern used by at least seven other panel drivers in the same Kconfig file (e.g., `DRM_PANEL_ILITEK_ILI9882T`, `DRM_PANEL_LG_SW43408`, `DRM_PANEL_NOVATEK_NT37801`, etc.). The fix is correct, minimal, and appropriately tagged with a `Fixes:` tag referencing the commit that introduced the driver.

**Verdict:** This patch is correct and ready to merge. No issues found.

---

---
Generated by Claude Code Patch Reviewer

Claude review: drm/panel: hx83121a: select DRM_DISPLAY_DSC_HELPER

[Claude Code Review Bot]

Patch Review

**Status: Good to merge**

The problem is clear: `panel-himax-hx83121a.c` includes `<drm/display/drm_dsc_helper.h>` and calls `drm_dsc_pps_payload_pack()` at line 116:

```c
drm_dsc_pps_payload_pack(&pps, &ctx->dsc);
```

But the Kconfig entry was missing the corresponding `select DRM_DISPLAY_DSC_HELPER`, causing a link-time failure:

```
undefined reference to `drm_dsc_pps_payload_pack'
```

The fix adds the missing `select`:

```diff
+	select DRM_DISPLAY_DSC_HELPER
 	select DRM_KMS_HELPER
```

The placement is correct — it's inserted alphabetically before `DRM_KMS_HELPER`, consistent with how other panel drivers order their `select` statements.

The `Fixes:` tag correctly references `a7c61963b727 ("drm/panel: Add Himax HX83121A panel driver")`, which is the commit that introduced the driver with the missing dependency.

No concerns with this patch.

---
Generated by Claude Code Patch Reviewer