On Fri, Apr 05, 2024 at 02:07:05PM +0530, Suraj Kandpal wrote:
> Limit minimum brightness to vbt min brightness when using aux
> based brightness control to avoid letting the screen
> from going completely blank.
> Sometimes vbt can have some bogus values hence clamping the value
> for sanity in case of corner case.
So, you're completely ignoring the value from the EDID now instead?
>
> --v2
> -Use something same mechanism to limit minimum brightness
> that PWM method uses [Jani]
>
> Signed-off-by: Suraj Kandpal <suraj.kand...@intel.com>
> ---
> drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> index 20dd5a6a0f3f..eb2a7225dfaa 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -411,6 +411,8 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector
> *connector, enum pipe pi
> struct intel_panel *panel = &connector->panel;
> struct drm_luminance_range_info *luminance_range =
> &connector->base.display_info.luminance_range;
> + u32 min_level = clamp_t(u32,
> + connector->panel.vbt.backlight.min_brightness,
> 0, 64);
> int ret;
>
> drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] SDR backlight is controlled
> through %s\n",
> @@ -427,14 +429,12 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector
> *connector, enum pipe pi
> }
> }
>
> - if (luminance_range->max_luminance) {
> + if (luminance_range->max_luminance)
> panel->backlight.max = luminance_range->max_luminance;
> - panel->backlight.min = luminance_range->min_luminance;
> - } else {
> + else
> panel->backlight.max = 512;
> - panel->backlight.min = 0;
> - }
>
> + panel->backlight.min = min_level;
> intel_dp_aux_write_panel_luminance_override(connector);
>
> drm_dbg_kms(&i915->drm, "[CONNECTOR:%d:%s] Using AUX HDR interface for
> backlight control (range %d..%d)\n",
