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_tv.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'drivers/gpu/drm/i915/intel_tv.c') diff --git a/drivers/gpu/drm/i915/intel_tv.c b/drivers/gpu/drm/i915/intel_tv.c index 6ed1a3ce47b7..e077c2a9e694 100644 --- a/drivers/gpu/drm/i915/intel_tv.c +++ b/drivers/gpu/drm/i915/intel_tv.c @@ -1315,8 +1315,10 @@ static void intel_tv_find_better_format(struct drm_connector *connector) * Currently this always returns CONNECTOR_STATUS_UNKNOWN, as we need to be sure * we have a pipe programmed in order to probe the TV. */ -static enum drm_connector_status -intel_tv_detect(struct drm_connector *connector, bool force) +static int +intel_tv_detect(struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx, + bool force) { struct drm_display_mode mode; struct intel_tv *intel_tv = intel_attached_tv(connector); @@ -1331,21 +1333,20 @@ intel_tv_detect(struct drm_connector *connector, bool force) if (force) { struct intel_load_detect_pipe tmp; - struct drm_modeset_acquire_ctx ctx; + int ret; - drm_modeset_acquire_init(&ctx, 0); + ret = intel_get_load_detect_pipe(connector, &mode, &tmp, ctx); + if (ret < 0) + return ret; - if (intel_get_load_detect_pipe(connector, &mode, &tmp, &ctx)) { + if (ret > 0) { type = intel_tv_detect_type(intel_tv, connector); - intel_release_load_detect_pipe(connector, &tmp, &ctx); + intel_release_load_detect_pipe(connector, &tmp, ctx); status = type < 0 ? connector_status_disconnected : connector_status_connected; } else status = connector_status_unknown; - - drm_modeset_drop_locks(&ctx); - drm_modeset_acquire_fini(&ctx); } else return connector->status; @@ -1516,7 +1517,6 @@ out: static const struct drm_connector_funcs intel_tv_connector_funcs = { .dpms = drm_atomic_helper_connector_dpms, - .detect = intel_tv_detect, .late_register = intel_connector_register, .early_unregister = intel_connector_unregister, .destroy = intel_tv_destroy, @@ -1528,6 +1528,7 @@ static const struct drm_connector_funcs intel_tv_connector_funcs = { }; static const struct drm_connector_helper_funcs intel_tv_connector_helper_funcs = { + .detect_ctx = intel_tv_detect, .mode_valid = intel_tv_mode_valid, .get_modes = intel_tv_get_modes, }; -- cgit v1.2.3-55-g7522