From d381baad29b43511a7fc34c64402ef65029ab281 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Jos=C3=A9=20Roberto=20de=20Souza?= Date: Thu, 8 Oct 2020 14:19:30 -0700 Subject: [PATCH] drm/i915/vbt: Fix backlight parsing for VBT 234+ MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Child min_brightness is obsolete from VBT 234+, instead the new min_brightness field in the main structure should be used. This new field is 16 bits wide, so backlight_precision_bits is needed to check if value needs to be scaled down but it is only available in VBT 236+ so working around it by using the also new backlight_level in the main struct. v2: - missed that backlight_data->level is also obsolete v3: - s/backlight/brightness to better match specification - using u16 to specify brightness level instead of a u32 : 16 BSpec: 20149 Reviewed-by: Matt Roper Signed-off-by: José Roberto de Souza Link: https://patchwork.freedesktop.org/patch/msgid/20201008211932.24989-1-jose.souza@intel.com --- drivers/gpu/drm/i915/display/intel_bios.c | 30 +++++++++++++++++++++++++-- drivers/gpu/drm/i915/display/intel_vbt_defs.h | 12 +++++++++-- 2 files changed, 38 insertions(+), 4 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index 5804eb9..b4d99d0 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -425,6 +425,7 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, const struct bdb_lfp_backlight_data *backlight_data; const struct lfp_backlight_data_entry *entry; int panel_type = dev_priv->vbt.panel_type; + u16 level; backlight_data = find_section(bdb, BDB_LVDS_BACKLIGHT); if (!backlight_data) @@ -459,14 +460,39 @@ parse_lfp_backlight(struct drm_i915_private *dev_priv, dev_priv->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz; dev_priv->vbt.backlight.active_low_pwm = entry->active_low_pwm; - dev_priv->vbt.backlight.min_brightness = entry->min_brightness; + + if (bdb->version >= 234) { + u16 min_level; + bool scale; + + level = backlight_data->brightness_level[panel_type].level; + min_level = backlight_data->brightness_min_level[panel_type].level; + + if (bdb->version >= 236) + scale = backlight_data->brightness_precision_bits[panel_type] == 16; + else + scale = level > 255; + + if (scale) + min_level = min_level / 255; + + if (min_level > 255) { + drm_warn(&dev_priv->drm, "Brightness min level > 255\n"); + level = 255; + } + dev_priv->vbt.backlight.min_brightness = min_level; + } else { + level = backlight_data->level[panel_type]; + dev_priv->vbt.backlight.min_brightness = entry->min_brightness; + } + drm_dbg_kms(&dev_priv->drm, "VBT backlight PWM modulation frequency %u Hz, " "active %s, min brightness %u, level %u, controller %u\n", dev_priv->vbt.backlight.pwm_freq_hz, dev_priv->vbt.backlight.active_low_pwm ? "low" : "high", dev_priv->vbt.backlight.min_brightness, - backlight_data->level[panel_type], + level, dev_priv->vbt.backlight.controller); } diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h index 54bcc6a..5df23e1 100644 --- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h +++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h @@ -782,7 +782,7 @@ struct lfp_backlight_data_entry { u8 active_low_pwm:1; u8 obsolete1:5; u16 pwm_freq_hz; - u8 min_brightness; + u8 min_brightness; /* Obsolete from 234+ */ u8 obsolete2; u8 obsolete3; } __packed; @@ -792,11 +792,19 @@ struct lfp_backlight_control_method { u8 controller:4; } __packed; +struct lfp_brightness_level { + u16 level; + u16 reserved; +} __packed; + struct bdb_lfp_backlight_data { u8 entry_size; struct lfp_backlight_data_entry data[16]; - u8 level[16]; + u8 level[16]; /* Obsolete from 234+ */ struct lfp_backlight_control_method backlight_control[16]; + struct lfp_brightness_level brightness_level[16]; /* 234+ */ + struct lfp_brightness_level brightness_min_level[16]; /* 234+ */ + u8 brightness_precision_bits[16]; /* 236+ */ } __packed; /* -- 2.7.4