Use struct member access instead of direct offsets to avoid lots of casts all over the place. Use BUILD_BUG_ON() for sanity check. Cc: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Signed-off-by: Jani Nikula <jani.nikula@xxxxxxxxx> --- drivers/gpu/drm/drm_edid.c | 27 ++++++++++++++++----------- 1 file changed, 16 insertions(+), 11 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index ac80681d64f6..586b0ed3b3dc 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2331,10 +2331,15 @@ struct drm_display_mode *drm_mode_find_dmt(struct drm_device *dev, } EXPORT_SYMBOL(drm_mode_find_dmt); -static bool is_display_descriptor(const u8 d[18], u8 tag) +static bool is_display_descriptor(const struct detailed_timing *descriptor, u8 tag) { - return d[0] == 0x00 && d[1] == 0x00 && - d[2] == 0x00 && d[3] == tag; + BUILD_BUG_ON(offsetof(typeof(*descriptor), data.descriptor.pad0) != 0); + BUILD_BUG_ON(offsetof(typeof(*descriptor), data.descriptor.pad1) != 2); + BUILD_BUG_ON(offsetof(typeof(*descriptor), data.descriptor.type) != 3); + + return descriptor->data.descriptor.pad0 == 0 && + descriptor->data.descriptor.pad1 == 0 && + descriptor->data.descriptor.type == tag; } static bool is_detailed_timing_descriptor(const u8 d[18]) @@ -2405,7 +2410,7 @@ is_rb(struct detailed_timing *t, void *data) { u8 *r = (u8 *)t; - if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE)) + if (!is_display_descriptor(t, EDID_DETAIL_MONITOR_RANGE)) return; if (r[10] == DRM_EDID_CVT_SUPPORT_FLAG && r[15] & 0x10) @@ -2431,7 +2436,7 @@ find_gtf2(struct detailed_timing *t, void *data) { u8 *r = (u8 *)t; - if (!is_display_descriptor(r, EDID_DETAIL_MONITOR_RANGE)) + if (!is_display_descriptor(t, EDID_DETAIL_MONITOR_RANGE)) return; if (r[10] == 0x02) @@ -2987,7 +2992,7 @@ do_inferred_modes(struct detailed_timing *timing, void *c) struct edid_display_descriptor *data = &timing->data.descriptor; struct detailed_data_monitor_range *range = &data->data.range; - if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE)) + if (!is_display_descriptor(timing, EDID_DETAIL_MONITOR_RANGE)) return; closure->modes += drm_dmt_modes_for_range(closure->connector, @@ -3067,7 +3072,7 @@ do_established_modes(struct detailed_timing *timing, void *c) { struct detailed_mode_closure *closure = c; - if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_EST_TIMINGS)) + if (!is_display_descriptor(timing, EDID_DETAIL_EST_TIMINGS)) return; closure->modes += drm_est3_modes(closure->connector, timing); @@ -3122,7 +3127,7 @@ do_standard_modes(struct detailed_timing *timing, void *c) struct edid *edid = closure->edid; int i; - if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_STD_MODES)) + if (!is_display_descriptor(timing, EDID_DETAIL_STD_MODES)) return; for (i = 0; i < 6; i++) { @@ -3231,7 +3236,7 @@ do_cvt_mode(struct detailed_timing *timing, void *c) { struct detailed_mode_closure *closure = c; - if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_CVT_3BYTE)) + if (!is_display_descriptor(timing, EDID_DETAIL_CVT_3BYTE)) return; closure->modes += drm_cvt_modes(closure->connector, timing); @@ -4491,7 +4496,7 @@ drm_parse_hdmi_vsdb_audio(struct drm_connector *connector, const u8 *db) static void monitor_name(struct detailed_timing *t, void *data) { - if (!is_display_descriptor((const u8 *)t, EDID_DETAIL_MONITOR_NAME)) + if (!is_display_descriptor(t, EDID_DETAIL_MONITOR_NAME)) return; *(u8 **)data = t->data.descriptor.data.str.str; @@ -5226,7 +5231,7 @@ void get_monitor_range(struct detailed_timing *timing, const struct edid_display_descriptor *data = &timing->data.descriptor; const struct detailed_data_monitor_range *range = &data->data.range; - if (!is_display_descriptor((const u8 *)timing, EDID_DETAIL_MONITOR_RANGE)) + if (!is_display_descriptor(timing, EDID_DETAIL_MONITOR_RANGE)) return; /* -- 2.30.2