drm/i915: add locking to fixed panel edid probing

With the recent addition of locking checks in

commit 62ff94a5492175759546f8bc61383189d6b49122
Author:     Daniel Vetter <daniel.vetter@ffwll.ch>
AuthorDate: Thu Jan 23 22:18:47 2014 +0100

    drm/crtc-helper: remove LOCKING from kerneldoc

drm_add_edid_modes started to WARN about the mode_config.mutex not
being held in the lvds and dp initialization code.

Now since this is init code locking is fairly redudant if it wouldn't
be for the drm core registering sysfs files a bit early. And the
locking WARNINGs nicely enforce that indeed all access to the mode
lists are properly protected. And a full audit shows that only i915
and gma500 touch the modes lists at init time.

Hence I've opted to wrap up this entire mode detection sequence for
fixed panels with the mode_config mutex for both lvds and edp outputs.

Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index 49d12d341ab2bf6886a1568081a15954dd9daefd..f2833de3f7a9906aa6c6854dfcc04ac3bafca24b 100644 (file)
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -3763,6 +3763,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
        /* We now know it's not a ghost, init power sequence regs. */
        intel_dp_init_panel_power_sequencer_registers(dev, intel_dp, power_seq);
 
+       mutex_lock(&dev->mode_config.mutex);
        edid = drm_get_edid(connector, &intel_dp->adapter);
        if (edid) {
                if (drm_add_edid_modes(connector, edid)) {
@@ -3793,6 +3794,7 @@ static bool intel_edp_init_connector(struct intel_dp *intel_dp,
                if (fixed_mode)
                        fixed_mode->type |= DRM_MODE_TYPE_PREFERRED;
        }
+       mutex_unlock(&dev->mode_config.mutex);
 
        intel_panel_init(&intel_connector->panel, fixed_mode, NULL);
        intel_panel_setup_backlight(connector);

diff --git a/drivers/gpu/drm/i915/intel_lvds.c b/drivers/gpu/drm/i915/intel_lvds.c
index fecff3c2b9e18aecc13435262def62312cb60037..48293d2cbf410be22707d2f88091bd0152f00f9d 100644 (file)
--- a/drivers/gpu/drm/i915/intel_lvds.c
+++ b/drivers/gpu/drm/i915/intel_lvds.c
@@ -1002,6 +1002,7 @@ void intel_lvds_init(struct drm_device *dev)
         * Attempt to get the fixed panel mode from DDC.  Assume that the
         * preferred mode is the right one.
         */
+       mutex_lock(&dev->mode_config.mutex);
        edid = drm_get_edid(connector, intel_gmbus_get_adapter(dev_priv, pin));
        if (edid) {
                if (drm_add_edid_modes(connector, edid)) {
@@ -1095,6 +1096,8 @@ void intel_lvds_init(struct drm_device *dev)
                goto failed;
 
 out:
+       mutex_unlock(&dev->mode_config.mutex);
+
        lvds_encoder->is_dual_link = compute_is_dual_link_lvds(lvds_encoder);
        DRM_DEBUG_KMS("detected %s-link lvds configuration\n",
                      lvds_encoder->is_dual_link ? "dual" : "single");
@@ -1123,6 +1126,8 @@ out:
        return;
 
 failed:
+       mutex_unlock(&dev->mode_config.mutex);
+
        DRM_DEBUG_KMS("No LVDS modes found, disabling.\n");
        drm_connector_cleanup(connector);
        drm_encoder_cleanup(encoder);