From 4da98541d898d45255edf874b16687aad0ff90cd Mon Sep 17 00:00:00 2001 From: Daniel Vetter Date: Fri, 21 Mar 2014 23:22:35 +0100 Subject: [PATCH] drm/i915: add locking to fixed panel edid probing With the recent addition of locking checks in commit 62ff94a5492175759546f8bc61383189d6b49122 Author: Daniel Vetter 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 --- drivers/gpu/drm/i915/intel_dp.c | 2 ++ drivers/gpu/drm/i915/intel_lvds.c | 5 +++++ 2 files changed, 7 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c index bbb1327644d4..7ca38e11e695 100644 --- a/drivers/gpu/drm/i915/intel_dp.c +++ b/drivers/gpu/drm/i915/intel_dp.c @@ -3646,6 +3646,7 @@ 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->aux.ddc); if (edid) { if (drm_add_edid_modes(connector, edid)) { @@ -3676,6 +3677,7 @@ 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 ef5e5661efb2..f1ecf916474a 100644 --- 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); -- 2.20.1