I found that writing to `/sys/kernel/debug/dri/*/eDP*/edid_override`
wasn't working for me. I could see the new EDID take effect in
`/sys/class/drm/card*-eDP*/edid` but userspace wasn't seeing it..
The problem was that panel-edp was caching the EDID that it read and
using that over and over again.
Let's change panel-edp to look at the EDID that's stored in the
connector. This is still a cache, which is important since this
function is called multiple times and readin the EDID is slow, but
this property is automatically updated by drm_get_edid() (which reads
the EDID) and also updated when writing the edid_override in debugfs.
Fixes: 63358e24ee79 ("drm/panel: panel-simple: Cache the EDID as long as we retain power")
Signed-off-by: Douglas Anderson <dianders@xxxxxxxxxxxx>
---
drivers/gpu/drm/panel/panel-edp.c | 21 ++++++++++++---------
1 file changed, 12 insertions(+), 9 deletions(-)
diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index 3626469c4cc2..12241c1e32f7 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -226,8 +226,6 @@ struct panel_edp {
const struct edp_panel_entry *detected_panel;
- struct edid *edid;
-
struct drm_display_mode override_mode;
enum drm_panel_orientation orientation;
@@ -580,11 +578,19 @@ static int panel_edp_get_modes(struct drm_panel *panel,
if (p->ddc) {
pm_runtime_get_sync(panel->dev);
- if (!p->edid)
- p->edid = drm_get_edid(connector, p->ddc);
+ if (!connector->edid_blob_ptr) {
+ /*
+ * We read the EDID and then immediately free it,
+ * relying on the side effect of drm_get_edid() to store
+ * a copy in connector->edid_blob_ptr. We always use
+ * the copy cached in the connector since that allows
+ * the edid_override to work.
+ */
+ kfree(drm_get_edid(connector, p->ddc));
+ }
- if (p->edid)
- num += drm_add_edid_modes(connector, p->edid);
+ if (connector->edid_blob_ptr)
+ num += drm_add_edid_modes(connector, connector->edid_blob_ptr->data);
pm_runtime_mark_last_busy(panel->dev);
pm_runtime_put_autosuspend(panel->dev);
@@ -926,9 +932,6 @@ static int panel_edp_remove(struct device *dev)
if (panel->ddc && (!panel->aux || panel->ddc != &panel->aux->ddc))
put_device(&panel->ddc->dev);
- kfree(panel->edid);
- panel->edid = NULL;
-
return 0;
}
--
2.37.0.170.g444d1eabd0-goog
