From 6c5ed5ae353cdf156f9ac4db17e15db56b4de880 Mon Sep 17 00:00:00 2001 From: Maarten Lankhorst Date: Thu, 6 Apr 2017 20:55:20 +0200 Subject: drm/atomic: Acquire connection_mutex lock in drm_helper_probe_single_connector_modes, v4. mode_valid() called from drm_helper_probe_single_connector_modes() may need to look at connector->state because what a valid mode is may depend on connector properties being set. For example some HDMI modes might be rejected when a connector property forces the connector into DVI mode. Some implementations of detect() already lock all state, so we have to pass an acquire_ctx to them to prevent a deadlock. This means changing the function signature of detect() slightly, and passing the acquire_ctx for locking multiple crtc's. For the callbacks, it will always be non-zero. To allow callers not to worry about this, drm_helper_probe_detect_ctx is added which might handle -EDEADLK for you. Changes since v1: - Always set ctx parameter. Changes since v2: - Always take connection_mutex when probing. Changes since v3: - Remove the ctx from intel_dp_long_pulse, and add WARN_ON(!connection_mutex) (danvet) - Update docs to clarify the locking situation. (danvet) Signed-off-by: Maarten Lankhorst Cc: Boris Brezillon Reviewed-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/1491504920-4017-1-git-send-email-maarten.lankhorst@linux.intel.com --- drivers/gpu/drm/i915/intel_crt.c | 25 ++++++++++++------------- 1 file changed, 12 insertions(+), 13 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_crt.c') diff --git a/drivers/gpu/drm/i915/intel_crt.c b/drivers/gpu/drm/i915/intel_crt.c index 8c82607294c6..2797bf37c3ac 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -669,15 +669,16 @@ static const struct dmi_system_id intel_spurious_crt_detect[] = { { } }; -static enum drm_connector_status -intel_crt_detect(struct drm_connector *connector, bool force) +static int +intel_crt_detect(struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx, + bool force) { struct drm_i915_private *dev_priv = to_i915(connector->dev); struct intel_crt *crt = intel_attached_crt(connector); struct intel_encoder *intel_encoder = &crt->base; - enum drm_connector_status status; + int status, ret; struct intel_load_detect_pipe tmp; - struct drm_modeset_acquire_ctx ctx; DRM_DEBUG_KMS("[CONNECTOR:%d:%s] force=%d\n", connector->base.id, connector->name, @@ -721,10 +722,9 @@ intel_crt_detect(struct drm_connector *connector, bool force) goto out; } - drm_modeset_acquire_init(&ctx, 0); - /* for pre-945g platforms use load detect */ - if (intel_get_load_detect_pipe(connector, NULL, &tmp, &ctx)) { + ret = intel_get_load_detect_pipe(connector, NULL, &tmp, ctx); + if (ret > 0) { if (intel_crt_detect_ddc(connector)) status = connector_status_connected; else if (INTEL_GEN(dev_priv) < 4) @@ -734,12 +734,11 @@ intel_crt_detect(struct drm_connector *connector, bool force) status = connector_status_disconnected; else status = connector_status_unknown; - intel_release_load_detect_pipe(connector, &tmp, &ctx); - } else + intel_release_load_detect_pipe(connector, &tmp, ctx); + } else if (ret == 0) status = connector_status_unknown; - - drm_modeset_drop_locks(&ctx); - drm_modeset_acquire_fini(&ctx); + else if (ret < 0) + status = ret; out: intel_display_power_put(dev_priv, intel_encoder->power_domain); @@ -811,7 +810,6 @@ void intel_crt_reset(struct drm_encoder *encoder) static const struct drm_connector_funcs intel_crt_connector_funcs = { .dpms = drm_atomic_helper_connector_dpms, - .detect = intel_crt_detect, .fill_modes = drm_helper_probe_single_connector_modes, .late_register = intel_connector_register, .early_unregister = intel_connector_unregister, @@ -823,6 +821,7 @@ static const struct drm_connector_funcs intel_crt_connector_funcs = { }; static const struct drm_connector_helper_funcs intel_crt_connector_helper_funcs = { + .detect_ctx = intel_crt_detect, .mode_valid = intel_crt_mode_valid, .get_modes = intel_crt_get_modes, }; -- cgit v1.2.3-59-g8ed1b