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 --- include/drm/drm_crtc_helper.h | 3 +++ 1 file changed, 3 insertions(+) (limited to 'include/drm/drm_crtc_helper.h') diff --git a/include/drm/drm_crtc_helper.h b/include/drm/drm_crtc_helper.h index 43505c7b2b3f..76e237bd989b 100644 --- a/include/drm/drm_crtc_helper.h +++ b/include/drm/drm_crtc_helper.h @@ -67,6 +67,9 @@ int drm_helper_crtc_mode_set_base(struct drm_crtc *crtc, int x, int y, int drm_helper_probe_single_connector_modes(struct drm_connector *connector, uint32_t maxX, uint32_t maxY); +int drm_helper_probe_detect(struct drm_connector *connector, + struct drm_modeset_acquire_ctx *ctx, + bool force); void drm_kms_helper_poll_init(struct drm_device *dev); void drm_kms_helper_poll_fini(struct drm_device *dev); bool drm_helper_hpd_irq_event(struct drm_device *dev); -- cgit v1.2.3