Re: [PATCH] drm: make panel orientation quirks optional

[Thomas Zimmermann <tzimmermann@suse.de>]

Hi

Am 16.07.26 um 08:51 schrieb Andrew Zhou:
> DRM currently selects DRM_PANEL_ORIENTATION_QUIRKS unconditionally,
> forcing all DRM users to compile embedded LCD panel quirk detection.
> This is unnecessary on desktop and server systems with external
> monitors.
>
> Add a static inline stub in drm_utils.h that returns
> DRM_MODE_PANEL_ORIENTATION_UNKNOWN when the option is disabled,
> and make the Kconfig option user-visible with a description.
>
> Compile-tested with CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y and =n.
> Boot-tested in QEMU with TinyCorePure64.

NAK. We also need these quirks on desktops, and disabling error 
workarounds makes little sense IMHO.

Best regards
Thomas

>
> Signed-off-by: Andrew Zhou <zhoulol888@gmail.com>
> ---
>   drivers/gpu/drm/Kconfig                        | 14 ++++++++++++--
>   drivers/gpu/drm/drm_panel_orientation_quirks.c |  6 ++++--
>   include/drm/drm_utils.h                        |  8 ++++++++
>   3 files changed, 24 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/Kconfig b/drivers/gpu/drm/Kconfig
> index 323422861e8f..da4ac94bbf61 100644
> --- a/drivers/gpu/drm/Kconfig
> +++ b/drivers/gpu/drm/Kconfig
> @@ -8,7 +8,6 @@
>   menuconfig DRM
>   	tristate "Direct Rendering Manager (XFree86 4.1.0 and higher DRI support)"
>   	depends on (AGP || AGP=n) && !EMULATED_CMPXCHG && HAS_DMA
> -	select DRM_PANEL_ORIENTATION_QUIRKS
>   	select HDMI
>   	select I2C
>   	select DMA_SHARED_BUFFER
> @@ -369,4 +368,15 @@ endif
>   
>   # Separate option because drm_panel_orientation_quirks.c is shared with fbdev
>   config DRM_PANEL_ORIENTATION_QUIRKS
> -	tristate
> +	tristate "Panel orientation quirks for DMI-based detection"
> +	depends on DRM
> +	help
> +	  Enable DMI-based quirk detection for devices where the
> +	  built-in LCD panel is mounted in a non-standard orientation
> +	  relative to the casing (e.g., handheld PCs, tablets).
> +
> +	  This allows userspace to automatically rotate the display
> +	  to match the physical orientation of the device.
> +
> +	  Desktop and server systems with external monitors do not
> +	  need this. If unsure, say N.
> diff --git a/drivers/gpu/drm/drm_panel_orientation_quirks.c b/drivers/gpu/drm/drm_panel_orientation_quirks.c
> index 3a218fb592ce..fb09078a831a 100644
> --- a/drivers/gpu/drm/drm_panel_orientation_quirks.c
> +++ b/drivers/gpu/drm/drm_panel_orientation_quirks.c
> @@ -14,7 +14,7 @@
>   #include <drm/drm_connector.h>
>   #include <drm/drm_utils.h>
>   
> -#ifdef CONFIG_DMI
> +#if defined(CONFIG_DMI) && defined(CONFIG_DRM_PANEL_ORIENTATION_QUIRKS)
>   
>   /*
>    * Some x86 clamshell design devices use portrait tablet screens and a display
> @@ -589,7 +589,7 @@ EXPORT_SYMBOL(drm_get_panel_orientation_quirk);
>   
>   #else
>   
> -/* There are no quirks for non x86 devices yet */
> +/* Fallback stub when DMI or the entire quirk module is disabled. */
>   int drm_get_panel_orientation_quirk(int width, int height)
>   {
>   	return DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
> @@ -598,5 +598,7 @@ EXPORT_SYMBOL(drm_get_panel_orientation_quirk);
>   
>   #endif
>   
> +#ifdef CONFIG_DRM_PANEL_ORIENTATION_QUIRKS
>   MODULE_DESCRIPTION("Quirks for non-normal panel orientation");
>   MODULE_LICENSE("Dual MIT/GPL");
> +#endif
> diff --git a/include/drm/drm_utils.h b/include/drm/drm_utils.h
> index 6a46f755daba..947b8e71260e 100644
> --- a/include/drm/drm_utils.h
> +++ b/include/drm/drm_utils.h
> @@ -11,10 +11,18 @@
>   #define __DRM_UTILS_H__
>   
>   #include <linux/types.h>
> +#include <drm/drm_connector.h>
>   
>   struct drm_edid;
>   
> +#ifdef CONFIG_DRM_PANEL_ORIENTATION_QUIRKS
>   int drm_get_panel_orientation_quirk(int width, int height);
> +#else
> +static inline int drm_get_panel_orientation_quirk(int width, int height)
> +{
> +	return DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
> +}
> +#endif
>   
>   struct drm_panel_backlight_quirk {
>   	u16 min_brightness;

-- 
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, (HRB 36809, AG Nürnberg)