From: Greg KH on
2.6.33-stable review patch. If anyone has any objections, please let us know.

------------------

From: Alex Deucher <alexdeucher(a)gmail.com>

commit 42f14c4b454946650cf0bf66e0b631d02e328f61 upstream.

This fixes a regression caused by b2ea4aa67bfd084834edd070e0a4a47857d6db59
due to the way shared ddc with multiple digital connectors was handled.

You generally have two cases where DDC lines are shared:
- HDMI + VGA
- HDMI + DVI-D

HDMI + VGA is easy to deal with because you can check the EDID for the
to see if the attached monitor is digital. A shared DDC line with two
digital connectors is more complex. You can't use the hdmi bits in the
EDID since they may not be there with DVI<->HDMI adapters. In this case
all we can do is check the HPD pins to see which is connected as we have
no way of knowing using the EDID.

Reported-by: trapdoor6(a)gmail.com
Signed-off-by: Alex Deucher <alexdeucher(a)gmail.com>
Signed-off-by: Dave Airlie <airlied(a)redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh(a)suse.de>

---
drivers/gpu/drm/radeon/radeon_connectors.c | 23 +++++++++--------------
1 file changed, 9 insertions(+), 14 deletions(-)

--- a/drivers/gpu/drm/radeon/radeon_connectors.c
+++ b/drivers/gpu/drm/radeon/radeon_connectors.c
@@ -779,14 +779,14 @@ static enum drm_connector_status radeon_
} else
ret = connector_status_connected;

- /* multiple connectors on the same encoder with the same ddc line
- * This tends to be HDMI and DVI on the same encoder with the
- * same ddc line. If the edid says HDMI, consider the HDMI port
- * connected and the DVI port disconnected. If the edid doesn't
- * say HDMI, vice versa.
+ /* This gets complicated. We have boards with VGA + HDMI with a
+ * shared DDC line and we have boards with DVI-D + HDMI with a shared
+ * DDC line. The latter is more complex because with DVI<->HDMI adapters
+ * you don't really know what's connected to which port as both are digital.
*/
if (radeon_connector->shared_ddc && (ret == connector_status_connected)) {
struct drm_device *dev = connector->dev;
+ struct radeon_device *rdev = dev->dev_private;
struct drm_connector *list_connector;
struct radeon_connector *list_radeon_connector;
list_for_each_entry(list_connector, &dev->mode_config.connector_list, head) {
@@ -796,15 +796,10 @@ static enum drm_connector_status radeon_
if (list_radeon_connector->shared_ddc &&
(list_radeon_connector->ddc_bus->rec.i2c_id ==
radeon_connector->ddc_bus->rec.i2c_id)) {
- if (drm_detect_hdmi_monitor(radeon_connector->edid)) {
- if (connector->connector_type == DRM_MODE_CONNECTOR_DVID) {
- kfree(radeon_connector->edid);
- radeon_connector->edid = NULL;
- ret = connector_status_disconnected;
- }
- } else {
- if ((connector->connector_type == DRM_MODE_CONNECTOR_HDMIA) ||
- (connector->connector_type == DRM_MODE_CONNECTOR_HDMIB)) {
+ /* cases where both connectors are digital */
+ if (list_connector->connector_type != DRM_MODE_CONNECTOR_VGA) {
+ /* hpd is our only option in this case */
+ if (!radeon_hpd_sense(rdev, radeon_connector->hpd.hpd)) {
kfree(radeon_connector->edid);
radeon_connector->edid = NULL;
ret = connector_status_disconnected;


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