drm/i915: don't disable the DP port if the link is lost

Currently if the DP link is lost (either because of a hot unplug, or
failed link status check) we disable the DP port, but leave the rest
of the pipe running. This is incompatible with the modeset disabling
sequence of some platforms/configurations. At least this is the case for
DP ports on the CPU as opposed to PCH.

Atm we'll also get a warning when we do a modeset disable after the
above link lost event, since we expect the DP port to be enabled at this
point (see the bugzilla ticket for the related dmesg).

Note that with this patch we'll still end up disabling the port, thanks
to the HPD uevent and subsequent modeset disable.

See also the next patch fixing the other half of this issue.

Solution suggested by Ville.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=70570
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 7df5085973e917ccd01c72487210621b78b783e9..7b630e9a0115edf3067ffdaea5b64e3b1c31e996 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -2891,13 +2891,11 @@ intel_dp_check_link_status(struct intel_dp *intel_dp)
 
        /* Try to read receiver status if the link appears to be up */
        if (!intel_dp_get_link_status(intel_dp, link_status)) {
-               intel_dp_link_down(intel_dp);
                return;
        }
 
        /* Now read the DPCD to see if it's actually running */
        if (!intel_dp_get_dpcd(intel_dp)) {
-               intel_dp_link_down(intel_dp);
                return;
        }