linux-kernel - [PATCH] drm/bridge: analogix_dp: Don't read EDID if panel present

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [day] [month] [year] [list]

Message-Id: <1472050706-32911-1-git-send-email-seanpaul@chromium.org>
Date:   Wed, 24 Aug 2016 10:58:26 -0400
From:   Sean Paul <seanpaul@...omium.org>
To:     dri-devel@...ts.freedesktop.org, ykk@...k-chips.com,
        yzq@...k-chips.com, thierry.reding@...il.com,
        architt@...eaurora.org
Cc:     tomeu.vizoso@...labora.com, daniel.vetter@...el.com,
        javier@....samsung.com, linux-kernel@...r.kernel.org,
        Sean Paul <seanpaul@...omium.org>
Subject: [PATCH] drm/bridge: analogix_dp: Don't read EDID if panel present

If there's a panel connected to the analogix_dp bridge, rely on
the panel driver for modes, rather than reading EDID *and* calling
get_modes() on the panel.

This allows panels with a valid EDID to read it in the panel driver
(e.g. simple_panel), and panels with invalid EDID to homebrew modes
in their get_modes implementation.

Signed-off-by: Sean Paul <seanpaul@...omium.org>
---

This patch is based on Tomeu's cleanup patch which can be found
here: https://patchwork.freedesktop.org/patch/107114/

 drivers/gpu/drm/bridge/analogix/analogix_dp_core.c | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
index 774cc796..e9c9aeb 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix_dp_core.c
@@ -930,15 +930,17 @@ int analogix_dp_get_modes(struct drm_connector *connector)
 		return 0;
 	}
 
-	edid = drm_get_edid(connector, &dp->aux.ddc);
-	if (edid) {
-		drm_mode_connector_update_edid_property(&dp->connector, edid);
-		num_modes += drm_add_edid_modes(&dp->connector, edid);
-		kfree(edid);
-	}
-
-	if (dp->plat_data->panel)
+	if (dp->plat_data->panel) {
 		num_modes += drm_panel_get_modes(dp->plat_data->panel);
+	} else {
+		edid = drm_get_edid(connector, &dp->aux.ddc);
+		if (edid) {
+			drm_mode_connector_update_edid_property(&dp->connector,
+								edid);
+			num_modes += drm_add_edid_modes(&dp->connector, edid);
+			kfree(edid);
+		}
+	}
 
 	if (dp->plat_data->get_modes)
 		num_modes += dp->plat_data->get_modes(dp->plat_data, connector);
-- 
2.8.0.rc3.226.g39d4020