drm/radeon/kms: don't disable shared encoders on pre-DCE3 display blocks

The A/B links aren't independantly useable on these blocks so when
we disable the encoders, make sure to only disable the encoder when
there is no connector using it.

Should fix:
https://bugs.freedesktop.org/show_bug.cgi?id=18564

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/radeon/radeon_encoders.c b/drivers/gpu/drm/radeon/radeon_encoders.c
index ae58b6849a2eaa4fd259b88f3d43d2497733161b..b862be61c398e47bc3fb58b7177b780641965208 100644 (file)
--- a/drivers/gpu/drm/radeon/radeon_encoders.c
+++ b/drivers/gpu/drm/radeon/radeon_encoders.c
@@ -1547,6 +1547,23 @@ static void radeon_atom_encoder_disable(struct drm_encoder *encoder)
        struct radeon_device *rdev = dev->dev_private;
        struct radeon_encoder *radeon_encoder = to_radeon_encoder(encoder);
        struct radeon_encoder_atom_dig *dig;
+
+       /* check for pre-DCE3 cards with shared encoders;
+        * can't really use the links individually, so don't disable
+        * the encoder if it's in use by another connector
+        */
+       if (!ASIC_IS_DCE3(rdev)) {
+               struct drm_encoder *other_encoder;
+               struct radeon_encoder *other_radeon_encoder;
+
+               list_for_each_entry(other_encoder, &dev->mode_config.encoder_list, head) {
+                       other_radeon_encoder = to_radeon_encoder(other_encoder);
+                       if ((radeon_encoder->encoder_id == other_radeon_encoder->encoder_id) &&
+                           drm_helper_encoder_in_use(other_encoder))
+                               goto disable_done;
+               }
+       }
+
        radeon_atom_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
 
        switch (radeon_encoder->encoder_id) {
@@ -1586,6 +1603,7 @@ static void radeon_atom_encoder_disable(struct drm_encoder *encoder)
                break;
        }
 
+disable_done:
        if (radeon_encoder_is_digital(encoder)) {
                if (atombios_get_encoder_mode(encoder) == ATOM_ENCODER_MODE_HDMI)
                        r600_hdmi_disable(encoder);