On Thu, 05 Jun 2025, Imre Deak <imre.d...@intel.com> wrote:
> Add support for EDID based quirks which can be queried outside of the
> EDID parser iteself by DRM core and drivers. There are at least two such
> quirks applicable to all drivers: the DPCD register access probe quirk
> and the 128b/132b DPRX Lane Count Conversion quirk (see 3.5.2.16.3 in
> the v2.1a DP Standard). The latter quirk applies to panels with specific
> EDID panel names, support for defining a quirk this way will be added as
> a follow-up.
>
> v2: Reset global_quirks in drm_reset_display_info().
> v3: (Jani)
> - Use one list for both the global and internal quirks.
> - Drop change for panel name specific quirks.
> - Add comment about the way quirks should be queried.
>
> Cc: Ville Syrjälä <ville.syrj...@linux.intel.com>
> Cc: Jani Nikula <jani.nik...@linux.intel.com>
> Signed-off-by: Imre Deak <imre.d...@intel.com>
> ---
> drivers/gpu/drm/drm_edid.c | 8 +++++++-
> include/drm/drm_connector.h | 4 +++-
> include/drm/drm_edid.h | 5 +++++
> 3 files changed, 15 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c
> index 857ae0c47a1c3..9cca1e6e4736c 100644
> --- a/drivers/gpu/drm/drm_edid.c
> +++ b/drivers/gpu/drm/drm_edid.c
> @@ -68,7 +68,7 @@ static int oui(u8 first, u8 second, u8 third)
>
> enum drm_edid_internal_quirk {
> /* First detailed mode wrong, use largest 60Hz mode */
> - EDID_QUIRK_PREFER_LARGE_60,
> + EDID_QUIRK_PREFER_LARGE_60 = DRM_EDID_QUIRK_NUM,
> /* Reported 135MHz pixel clock is too high, needs adjustment */
> EDID_QUIRK_135_CLOCK_TOO_HIGH,
> /* Prefer the largest mode at 75 Hz */
> @@ -2959,6 +2959,12 @@ static bool drm_edid_has_internal_quirk(struct
> drm_connector *connector,
> return connector->display_info.quirks & BIT(quirk);
> }
>
> +bool drm_edid_has_quirk(struct drm_connector *connector, enum drm_edid_quirk
> quirk)
Nitpick, this could've been const.
Regardless,
Reviewed-by: Jani Nikula <jani.nik...@intel.com>
> +{
> + return connector->display_info.quirks & BIT(quirk);
> +}
> +EXPORT_SYMBOL(drm_edid_has_quirk);
> +
> #define MODE_SIZE(m) ((m)->hdisplay * (m)->vdisplay)
> #define MODE_REFRESH_DIFF(c,t) (abs((c) - (t)))
>
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 73903c3c842f3..137773dd138ea 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -843,7 +843,9 @@ struct drm_display_info {
> int vics_len;
>
> /**
> - * @quirks: EDID based quirks. Internal to EDID parsing.
> + * @quirks: EDID based quirks. DRM core and drivers can query the
> + * @drm_edid_quirk quirks using drm_edid_has_quirk(), the rest of
> + * the quirks also tracked here are internal to EDID parsing.
> */
> u32 quirks;
>
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index b38409670868d..77fd42608e706 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -109,6 +109,10 @@ struct detailed_data_string {
> #define DRM_EDID_CVT_FLAGS_STANDARD_BLANKING (1 << 3)
> #define DRM_EDID_CVT_FLAGS_REDUCED_BLANKING (1 << 4)
>
> +enum drm_edid_quirk {
> + DRM_EDID_QUIRK_NUM,
> +};
> +
> struct detailed_data_monitor_range {
> u8 min_vfreq;
> u8 max_vfreq;
> @@ -476,5 +480,6 @@ void drm_edid_print_product_id(struct drm_printer *p,
> u32 drm_edid_get_panel_id(const struct drm_edid *drm_edid);
> bool drm_edid_match(const struct drm_edid *drm_edid,
> const struct drm_edid_ident *ident);
> +bool drm_edid_has_quirk(struct drm_connector *connector, enum drm_edid_quirk
> quirk);
>
> #endif /* __DRM_EDID_H__ */
--
Jani Nikula, Intel
