From 58b2e3829ec6558d6d0edf709579b82550ecea61 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 5 Apr 2022 20:33:53 +0300 Subject: [PATCH] drm/i915/bios: Trust the LFP data pointers MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Now that we've sufficiently validated the LFP data pointers we can trust them. Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20220405173410.11436-6-ville.syrjala@linux.intel.com Reviewed-by: Jani Nikula --- drivers/gpu/drm/i915/display/intel_bios.c | 60 +++++++++---------------------- 1 file changed, 16 insertions(+), 44 deletions(-) diff --git a/drivers/gpu/drm/i915/display/intel_bios.c b/drivers/gpu/drm/i915/display/intel_bios.c index de1c4be..762acf8 100644 --- a/drivers/gpu/drm/i915/display/intel_bios.c +++ b/drivers/gpu/drm/i915/display/intel_bios.c @@ -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); -- 2.7.4