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drm/i915/bios: Trust the LFP data pointers

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Now that we've sufficiently validated the LFP data pointers we
can trust them.

Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220405173410.11436-6-ville.syrjala@linux.intel.com
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
This commit is contained in:
Ville Syrjälä 2022-04-05 20:33:53 +03:00
parent 514003e142
commit 58b2e3829e
1 changed files with 16 additions and 44 deletions
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60
drivers/gpu/drm/i915/display/intel_bios.c
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@ -397,44 +397,19 @@ fill_detail_timing_data(struct drm_display_mode *panel_fixed_mode,
}
static const struct lvds_dvo_timing *
get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *lvds_lfp_data,
const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs,
get_lvds_dvo_timing(const struct bdb_lvds_lfp_data *data,
const struct bdb_lvds_lfp_data_ptrs *ptrs,
int index)
{
/*
* the size of fp_timing varies on the different platform.
* So calculate the DVO timing relative offset in LVDS data
* entry to get the DVO timing entry
*/
int lfp_data_size =
lvds_lfp_data_ptrs->ptr[1].dvo_timing.offset -
lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset;
int dvo_timing_offset =
lvds_lfp_data_ptrs->ptr[0].dvo_timing.offset -
lvds_lfp_data_ptrs->ptr[0].fp_timing.offset;
char *entry = (char *)lvds_lfp_data->data + lfp_data_size * index;
return (struct lvds_dvo_timing *)(entry + dvo_timing_offset);
return (const void *)data + ptrs->ptr[index].dvo_timing.offset;
}
/* get lvds_fp_timing entry
* this function may return NULL if the corresponding entry is invalid
*/
static const struct lvds_fp_timing *
get_lvds_fp_timing(const struct bdb_lvds_lfp_data *data,
const struct bdb_lvds_lfp_data_ptrs *ptrs,
int index)
{
u16 data_size = ((const u16 *)data)[-1]; /* stored in header */
size_t ofs;
if (index >= ARRAY_SIZE(ptrs->ptr))
return NULL;
ofs = ptrs->ptr[index].fp_timing.offset;
if (ofs + sizeof(struct lvds_fp_timing) > data_size)
return NULL;
return (const struct lvds_fp_timing *)((const u8 *)data + ofs);
return (const void *)data + ptrs->ptr[index].fp_timing.offset;
}
/* Parse general panel options */
@ -499,8 +474,7 @@ parse_panel_options(struct drm_i915_private *i915)
/* Try to find integrated panel timing data */
static void
parse_lfp_panel_dtd(struct drm_i915_private *i915,
const struct bdb_header *bdb)
parse_lfp_panel_dtd(struct drm_i915_private *i915)
{
const struct bdb_lvds_lfp_data *lvds_lfp_data;
const struct bdb_lvds_lfp_data_ptrs *lvds_lfp_data_ptrs;
@ -536,15 +510,14 @@ parse_lfp_panel_dtd(struct drm_i915_private *i915,
fp_timing = get_lvds_fp_timing(lvds_lfp_data,
lvds_lfp_data_ptrs,
panel_type);
if (fp_timing) {
/* check the resolution, just to be sure */
if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
fp_timing->y_res == panel_fixed_mode->vdisplay) {
i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
drm_dbg_kms(&i915->drm,
"VBT initial LVDS value %x\n",
i915->vbt.bios_lvds_val);
}
/* check the resolution, just to be sure */
if (fp_timing->x_res == panel_fixed_mode->hdisplay &&
fp_timing->y_res == panel_fixed_mode->vdisplay) {
i915->vbt.bios_lvds_val = fp_timing->lvds_reg_val;
drm_dbg_kms(&i915->drm,
"VBT initial LVDS value %x\n",
i915->vbt.bios_lvds_val);
}
}
@ -627,8 +600,7 @@ parse_generic_dtd(struct drm_i915_private *i915)
}
static void
parse_panel_dtd(struct drm_i915_private *i915,
const struct bdb_header *bdb)
parse_panel_dtd(struct drm_i915_private *i915)
{
/*
* Older VBTs provided provided DTD information for internal displays
@ -641,7 +613,7 @@ parse_panel_dtd(struct drm_i915_private *i915,
if (i915->vbt.version >= 229)
parse_generic_dtd(i915);
if (!i915->vbt.lfp_lvds_vbt_mode)
parse_lfp_panel_dtd(i915, bdb);
parse_lfp_panel_dtd(i915);
}
static void
@ -2720,7 +2692,7 @@ void intel_bios_init(struct drm_i915_private *i915)
parse_general_features(i915);
parse_general_definitions(i915);
parse_panel_options(i915);
parse_panel_dtd(i915, bdb);
parse_panel_dtd(i915);
parse_lfp_backlight(i915);
parse_sdvo_panel_data(i915);
parse_driver_features(i915);