On 04/04/2023 12:47, AngeloGioacchino Del Regno wrote:
Since eDP panels are not removable it is safe to cache the EDID:
this will avoid a relatively long read transaction at every PM
resume that is unnecessary only in the "special" case of eDP,
hence speeding it up a little, as from now on, as resume operation,
we will perform only link training.
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@xxxxxxxxxxxxx>
---
drivers/gpu/drm/mediatek/mtk_dp.c | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/mediatek/mtk_dp.c b/drivers/gpu/drm/mediatek/mtk_dp.c
index 1f94fcc144d3..84f82cc68672 100644
--- a/drivers/gpu/drm/mediatek/mtk_dp.c
+++ b/drivers/gpu/drm/mediatek/mtk_dp.c
@@ -118,6 +118,7 @@ struct mtk_dp {
const struct mtk_dp_data *data;
struct mtk_dp_info info;
struct mtk_dp_train_info train_info;
+ struct edid *edid;
struct platform_device *phy_dev;
struct phy *phy;
@@ -1993,7 +1994,11 @@ static struct edid *mtk_dp_get_edid(struct drm_bridge *bridge,
usleep_range(2000, 5000);
}
- new_edid = drm_get_edid(connector, &mtk_dp->aux.ddc);
+ /* eDP panels aren't removable, so we can return a cached EDID. */
+ if (mtk_dp->edid && mtk_dp->bridge.type == DRM_MODE_CONNECTOR_eDP)
+ new_edid = drm_edid_duplicate(mtk_dp->edid);
+ else
+ new_edid = drm_get_edid(connector, &mtk_dp->aux.ddc);
Maybe it would make sense to add a macro for the check of mtk_dp->bridge.type ==
DRM_MODE_CONNECTOR_eDP
it would make the code more readable.
/*
* Parse capability here to let atomic_get_input_bus_fmts and
@@ -2022,6 +2027,10 @@ static struct edid *mtk_dp_get_edid(struct drm_bridge *bridge,
drm_atomic_bridge_chain_post_disable(bridge, connector->state->state);
}
+ /* If this is an eDP panel and the read EDID is good, cache it for later */
+ if (mtk_dp->bridge.type == DRM_MODE_CONNECTOR_eDP && !mtk_dp->edid && new_edid)
+ mtk_dp->edid = drm_edid_duplicate(new_edid);
+
How about putting this in an else if branch of mtk_dp_parse_capabilities. At
least we could get rid of the check regarding if new_edid != NULL.
I was thinking on how to put both if statements in one block, but I think the
problem is, that we would leak memory if the capability parsing failes due to
the call to drm_edid_duplicate(). Correct?
Regards,
Matthais
return new_edid;
}. /
