From 0d32da3cee76cd6b48ad3c81e1297a4318e22a75 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 31afb681d7fbf9e1296c54cb689ff3bedd21a225 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 Signed-off-by: Dave Airlie --- 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 49d12d341ab2b..f2833de3f7a99 100644 --- 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 fecff3c2b9e18..48293d2cbf410 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); -- 2.39.5