From 208bf9fdcd3575aa4a5d48b3e0295f7cdaf6fc44 Mon Sep 17 00:00:00 2001 From: Ville Syrjälä Date: Mon, 11 Aug 2014 13:15:35 +0300 Subject: drm/i915: Fix locking for intel_enable_pipe_a() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 --- drivers/gpu/drm/i915/intel_crt.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (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 2efaf8e8d9c..e8abfce4097 100644 --- a/drivers/gpu/drm/i915/intel_crt.c +++ b/drivers/gpu/drm/i915/intel_crt.c @@ -699,16 +699,21 @@ 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)) { if (intel_crt_detect_ddc(connector)) status = connector_status_connected; else status = intel_crt_load_detect(crt); - intel_release_load_detect_pipe(connector, &tmp, &ctx); + intel_release_load_detect_pipe(connector, &tmp); } else status = connector_status_unknown; + drm_modeset_drop_locks(&ctx); + drm_modeset_acquire_fini(&ctx); + out: intel_display_power_put(dev_priv, power_domain); return status; -- cgit v1.2.3-70-g09d2