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authorLukasz Majczak <lma@semihalf.com>2021-09-30 15:46:06 +0200
committerJani Nikula <jani.nikula@intel.com>2021-10-05 11:52:48 +0300
commitfdddf8c3a477f77b3a623f220e78d45e89fc50d5 (patch)
tree8705aaa68316629ea9eddaebbfcba99dba1215ec /drivers/gpu/drm/i915/display
parenta532cde31de3cae6ed60e60d6f9379771f652809 (diff)
drm/i915/bdb: Fix version check
With patch "drm/i915/vbt: Fix backlight parsing for VBT 234+" the size of bdb_lfp_backlight_data structure has been increased, causing if-statement in the parse_lfp_backlight function that comapres this structure size to the one retrieved from BDB, always to fail for older revisions. This patch calculates expected size of the structure for a given BDB version and compares it with the value gathered from BDB. Tested on Chromebook Pixelbook (Nocturne) (reports bdb->version = 221) Fixes: d381baad29b4 ("drm/i915/vbt: Fix backlight parsing for VBT 234+") Tested-by: Lukasz Majczak <lma@semihalf.com> Signed-off-by: Lukasz Majczak <lma@semihalf.com> Reviewed-by: José Roberto de Souza <jose.souza@intel.com> Signed-off-by: José Roberto de Souza <jose.souza@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210930134606.227234-1-lma@semihalf.com (cherry picked from commit 4378daf5d04eed59724e6d0e74755e17dce2e105) Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/display')
-rw-r--r--drivers/gpu/drm/i915/display/intel_bios.c22
-rw-r--r--drivers/gpu/drm/i915/display/intel_vbt_defs.h5
2 files changed, 21 insertions, 6 deletions
diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c
index e86e6ed2d3bf..fd71346aac7b 100644
--- a/drivers/gpu/drm/i915/display/intel_bios.c
+++ b/drivers/gpu/drm/i915/display/intel_bios.c
@@ -451,13 +451,23 @@ parse_lfp_backlight(struct drm_i915_private *i915,
}
i915->vbt.backlight.type = INTEL_BACKLIGHT_DISPLAY_DDI;
- if (bdb->version >= 191 &&
- get_blocksize(backlight_data) >= sizeof(*backlight_data)) {
- const struct lfp_backlight_control_method *method;
+ if (bdb->version >= 191) {
+ size_t exp_size;
- method = &backlight_data->backlight_control[panel_type];
- i915->vbt.backlight.type = method->type;
- i915->vbt.backlight.controller = method->controller;
+ if (bdb->version >= 236)
+ exp_size = sizeof(struct bdb_lfp_backlight_data);
+ else if (bdb->version >= 234)
+ exp_size = EXP_BDB_LFP_BL_DATA_SIZE_REV_234;
+ else
+ exp_size = EXP_BDB_LFP_BL_DATA_SIZE_REV_191;
+
+ if (get_blocksize(backlight_data) >= exp_size) {
+ const struct lfp_backlight_control_method *method;
+
+ method = &backlight_data->backlight_control[panel_type];
+ i915->vbt.backlight.type = method->type;
+ i915->vbt.backlight.controller = method->controller;
+ }
}
i915->vbt.backlight.pwm_freq_hz = entry->pwm_freq_hz;
diff --git a/drivers/gpu/drm/i915/display/intel_vbt_defs.h b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
index 330077c2e588..a2108a8f544d 100644
--- a/drivers/gpu/drm/i915/display/intel_vbt_defs.h
+++ b/drivers/gpu/drm/i915/display/intel_vbt_defs.h
@@ -814,6 +814,11 @@ struct lfp_brightness_level {
u16 reserved;
} __packed;
+#define EXP_BDB_LFP_BL_DATA_SIZE_REV_191 \
+ offsetof(struct bdb_lfp_backlight_data, brightness_level)
+#define EXP_BDB_LFP_BL_DATA_SIZE_REV_234 \
+ offsetof(struct bdb_lfp_backlight_data, brightness_precision_bits)
+
struct bdb_lfp_backlight_data {
u8 entry_size;
struct lfp_backlight_data_entry data[16];