Re: [RFC v3 06/10] drm/i915/dpcd_bl: Cache some backlight capabilities in intel_panel.backlight

From: Rodrigo Vivi
Date: Mon Feb 08 2021 - 06:31:09 EST


On Fri, Feb 05, 2021 at 06:45:10PM -0500, Lyude Paul wrote:
> Since we're about to be moving this code into shared DRM helpers, we might
> as well start to cache certain backlight capabilities that can be
> determined from the EDP DPCD, and are likely to be relevant to the majority
> of drivers using said helpers. The main purpose of this is just to prevent
> every driver from having to check everything against the eDP DPCD using DP
> macros, which makes the code slightly easier to read (especially since the
> names of some of the eDP capabilities don't exactly match up with what we
> actually need to use them for, like DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT
> for instance).
>
> Signed-off-by: Lyude Paul <lyude@xxxxxxxxxx>

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx>

> ---
> .../drm/i915/display/intel_display_types.h | 2 ++
> .../drm/i915/display/intel_dp_aux_backlight.c | 29 ++++++++++++-------
> 2 files changed, 21 insertions(+), 10 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/display/intel_display_types.h b/drivers/gpu/drm/i915/display/intel_display_types.h
> index f4b26e1dbaaf..16824eb3ef93 100644
> --- a/drivers/gpu/drm/i915/display/intel_display_types.h
> +++ b/drivers/gpu/drm/i915/display/intel_display_types.h
> @@ -265,6 +265,8 @@ struct intel_panel {
> struct {
> u8 pwmgen_bit_count;
> u8 pwm_freq_pre_divider;
> + bool lsb_reg_used;
> + bool aux_enable;
> } vesa;
> struct {
> bool sdr_uses_aux;
> 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 95e3e344cf40..f5ae2fb34c1f 100644
> --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c
> @@ -270,13 +270,14 @@ intel_dp_aux_hdr_setup_backlight(struct intel_connector *connector, enum pipe pi
> }
>
> /* VESA backlight callbacks */
> -static void set_vesa_backlight_enable(struct intel_dp *intel_dp, bool enable)
> +static void set_vesa_backlight_enable(struct intel_connector *connector, bool enable)
> {
> + struct intel_dp *intel_dp = intel_attached_dp(connector);
> struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> u8 reg_val = 0;
>
> /* Early return when display use other mechanism to enable backlight. */
> - if (!(intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP))
> + if (!connector->panel.backlight.edp.vesa.aux_enable)
> return;
>
> if (drm_dp_dpcd_readb(&intel_dp->aux, DP_EDP_DISPLAY_CONTROL_REGISTER, &reg_val) != 1) {
> @@ -339,9 +340,11 @@ static u32 intel_dp_aux_vesa_get_backlight(struct intel_connector *connector, en
> DP_EDP_BACKLIGHT_BRIGHTNESS_MSB);
> return 0;
> }
> - level = read_val[0];
> - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
> +
> + if (connector->panel.backlight.edp.vesa.lsb_reg_used)
> level = (read_val[0] << 8 | read_val[1]);
> + else
> + level = read_val[0];
>
> return level;
> }
> @@ -359,13 +362,14 @@ intel_dp_aux_vesa_set_backlight(const struct drm_connector_state *conn_state,
> struct drm_i915_private *i915 = dp_to_i915(intel_dp);
> u8 vals[2] = { 0x0 };
>
> - vals[0] = level;
> -
> /* Write the MSB and/or LSB */
> - if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT) {
> + if (connector->panel.backlight.edp.vesa.lsb_reg_used) {
> vals[0] = (level & 0xFF00) >> 8;
> vals[1] = (level & 0xFF);
> + } else {
> + vals[0] = level;
> }
> +
> if (drm_dp_dpcd_write(&intel_dp->aux, DP_EDP_BACKLIGHT_BRIGHTNESS_MSB, vals,
> sizeof(vals)) != sizeof(vals)) {
> drm_dbg_kms(&i915->drm,
> @@ -419,14 +423,13 @@ intel_dp_aux_vesa_enable_backlight(const struct intel_crtc_state *crtc_state,
> }
>
> intel_dp_aux_vesa_set_backlight(conn_state, level);
> - set_vesa_backlight_enable(intel_dp, true);
> + set_vesa_backlight_enable(connector, true);
> }
>
> static void intel_dp_aux_vesa_disable_backlight(const struct drm_connector_state *old_conn_state,
> u32 level)
> {
> - set_vesa_backlight_enable(enc_to_intel_dp(to_intel_encoder(old_conn_state->best_encoder)),
> - false);
> + set_vesa_backlight_enable(to_intel_connector(old_conn_state->connector), false);
> }
>
> /*
> @@ -524,8 +527,14 @@ static u32 intel_dp_aux_vesa_calc_max_backlight(struct intel_connector *connecto
> static int intel_dp_aux_vesa_setup_backlight(struct intel_connector *connector,
> enum pipe pipe)
> {
> + struct intel_dp *intel_dp = intel_attached_dp(connector);
> struct intel_panel *panel = &connector->panel;
>
> + if (intel_dp->edp_dpcd[1] & DP_EDP_BACKLIGHT_AUX_ENABLE_CAP)
> + panel->backlight.edp.vesa.aux_enable = true;
> + if (intel_dp->edp_dpcd[2] & DP_EDP_BACKLIGHT_BRIGHTNESS_BYTE_COUNT)
> + panel->backlight.edp.vesa.lsb_reg_used = true;
> +
> panel->backlight.max = intel_dp_aux_vesa_calc_max_backlight(connector);
> if (!panel->backlight.max)
> return -ENODEV;
> --
> 2.29.2
>
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel