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From:   Hsin-Yi Wang <hsinyi@chromium.org>
To:     Douglas Anderson <dianders@chromium.org>
Cc:     Neil Armstrong <neil.armstrong@linaro.org>,
        Jessica Zhang <quic_jesszhan@quicinc.com>,
        Sam Ravnborg <sam@ravnborg.org>,
        Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
        Maxime Ripard <mripard@kernel.org>,
        Thomas Zimmermann <tzimmermann@suse.de>,
        David Airlie <airlied@gmail.com>,
        Daniel Vetter <daniel@ffwll.ch>,
        dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org,
        stable@vger.kernel.org
Subject: [PATCH v7 1/3] drm/panel-edp: Add override_edid_mode quirk for generic edp
Date:   Fri, 17 Nov 2023 13:46:32 -0800
Message-ID: <20231117215056.1883314-2-hsinyi@chromium.org>
In-Reply-To: <20231117215056.1883314-1-hsinyi@chromium.org>
References: <20231117215056.1883314-1-hsinyi@chromium.org>
MIME-Version: 1.0
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Precedence: bulk

Generic edp gets mode from edid. However, some panels report incorrect
mode in this way, resulting in glitches on panel. Introduce a new quirk
additional_mode to the generic edid to pick a correct hardcoded mode.

Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---
v6->v7: split usecase to another patch.
---
 drivers/gpu/drm/panel/panel-edp.c | 48 +++++++++++++++++++++++++++++--
 1 file changed, 45 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/panel/panel-edp.c b/drivers/gpu/drm/panel/panel-edp.c
index f22677373171..33535f6de343 100644
--- a/drivers/gpu/drm/panel/panel-edp.c
+++ b/drivers/gpu/drm/panel/panel-edp.c
@@ -203,6 +203,9 @@ struct edp_panel_entry {
 
 	/** @name: Name of this panel (for printing to logs). */
 	const char *name;
+
+	/** @override_edid_mode: Override the mode obtained by edid. */
+	const struct drm_display_mode *override_edid_mode;
 };
 
 struct panel_edp {
@@ -301,6 +304,24 @@ static unsigned int panel_edp_get_display_modes(struct panel_edp *panel,
 	return num;
 }
 
+static int panel_edp_override_edid_mode(struct panel_edp *panel,
+					struct drm_connector *connector,
+					const struct drm_display_mode *override_mode)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, override_mode);
+	if (!mode) {
+		dev_err(panel->base.dev, "failed to add additional mode\n");
+		return 0;
+	}
+
+	mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+	return 1;
+}
+
 static int panel_edp_get_non_edid_modes(struct panel_edp *panel,
 					struct drm_connector *connector)
 {
@@ -568,6 +589,9 @@ static int panel_edp_get_modes(struct drm_panel *panel,
 {
 	struct panel_edp *p = to_panel_edp(panel);
 	int num = 0;
+	bool has_override_edid_mode = p->detected_panel &&
+				      p->detected_panel != ERR_PTR(-EINVAL) &&
+				      p->detected_panel->override_edid_mode;
 
 	/* probe EDID if a DDC bus is available */
 	if (p->ddc) {
@@ -575,9 +599,18 @@ static int panel_edp_get_modes(struct drm_panel *panel,
 
 		if (!p->edid)
 			p->edid = drm_get_edid(connector, p->ddc);
-
-		if (p->edid)
-			num += drm_add_edid_modes(connector, p->edid);
+		if (p->edid) {
+			if (has_override_edid_mode) {
+				/*
+				 * override_edid_mode is specified. Use
+				 * override_edid_mode instead of from edid.
+				 */
+				num += panel_edp_override_edid_mode(p, connector,
+						p->detected_panel->override_edid_mode);
+			} else {
+				num += drm_add_edid_modes(connector, p->edid);
+			}
+		}
 
 		pm_runtime_mark_last_busy(panel->dev);
 		pm_runtime_put_autosuspend(panel->dev);
@@ -1849,6 +1882,15 @@ static const struct panel_delay delay_200_150_e200 = {
 	.delay = _delay \
 }
 
+#define EDP_PANEL_ENTRY2(vend_chr_0, vend_chr_1, vend_chr_2, product_id, _delay, _name, _mode) \
+{ \
+	.name = _name, \
+	.panel_id = drm_edid_encode_panel_id(vend_chr_0, vend_chr_1, vend_chr_2, \
+					     product_id), \
+	.delay = _delay, \
+	.override_edid_mode = _mode \
+}
+
 /*
  * This table is used to figure out power sequencing delays for panels that
  * are detected by EDID. Entries here may point to entries in the
-- 
2.43.0.rc0.421.g78406f8d94-goog