From 208bf9fdcd3575aa4a5d48b3e0295f7cdaf6fc44 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Mon, 11 Aug 2014 13:15:35 +0300 Subject: [PATCH] drm/i915: Fix locking for intel_enable_pipe_a() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit intel_enable_pipe_a() gets called with all the modeset locks already held (by drm_modeset_lock_all()), so trying to grab the same locks using another drm_modeset_acquire_ctx is going to fail miserably. Move most of the drm_modeset_acquire_ctx handling (init/drop/fini) out from intel_{get,release}_load_detect_pipe() into the callers (intel_{crt,tv}_detect()). Only the actual locking and backoff handling is left in intel_get_load_detect_pipe(). And in intel_enable_pipe_a() we just share the mode_config.acquire_ctx from drm_modeset_lock_all() which is already holding all the relevant locks. It's perfectly legal to lock the same ww_mutex multiple times using the same ww_acquire_ctx. drm_modeset_lock() will convert the returned -EALREADY into 0, so the caller doesn't need to do antyhing special. Fixes a hang on resume on my 830. Signed-off-by: Ville Syrjälä Reviewed-by: Daniel Vetter Cc: stable@vger.kernel.org Signed-off-by: Jani Nikula --- Reading git-format-patch failed