[PATCH v7 3/3] drm/panel-edp: Avoid adding multiple preferred modes

From: Hsin-Yi Wang
Date: Fri Nov 17 2023 - 16:51:17 EST


If a non generic edp-panel is under aux-bus, the mode read from edid would
still be selected as preferred and results in multiple preferred modes,
which is ambiguous.

If both hard-coded mode and edid exists, only add mode from hard-coded.

Signed-off-by: Hsin-Yi Wang <hsinyi@xxxxxxxxxxxx>
Reviewed-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
v6->v7: no change
---
drivers/gpu/drm/panel/panel-edp.c | 14 +++++++-------
1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 3e144145a6bd..825fa2a0d8a5 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -589,6 +589,7 @@ static int panel_edp_get_modes(struct drm_panel *panel,
{
struct panel_edp *p = to_panel_edp(panel);
int num = 0;
+ bool has_hard_coded_modes = p->desc->num_timings || p->desc->num_modes;
bool has_override_edid_mode = p->detected_panel &&
p->detected_panel != ERR_PTR(-EINVAL) &&
p->detected_panel->override_edid_mode;
@@ -599,7 +600,11 @@ static int panel_edp_get_modes(struct drm_panel *panel,

if (!p->edid)
p->edid = drm_get_edid(connector, p->ddc);
- if (p->edid) {
+ /*
+ * If both edid and hard-coded modes exists, skip edid modes to
+ * avoid multiple preferred modes.
+ */
+ if (p->edid && !has_hard_coded_modes) {
if (has_override_edid_mode) {
/*
* override_edid_mode is specified. Use
@@ -616,12 +621,7 @@ static int panel_edp_get_modes(struct drm_panel *panel,
pm_runtime_put_autosuspend(panel->dev);
}

- /*
- * Add hard-coded panel modes. Don't call this if there are no timings
- * and no modes (the generic edp-panel case) because it will clobber
- * the display_info that was already set by drm_add_edid_modes().
- */
- if (p->desc->num_timings || p->desc->num_modes)
+ if (has_hard_coded_modes)
num += panel_edp_get_non_edid_modes(p, connector);
else if (!num)
dev_warn(p->base.dev, "No display modes\n");
--
2.43.0.rc0.421.g78406f8d94-goog