From: Chris Wilson Date: Tue, 6 Dec 2016 11:37:15 +0000 (+0000) Subject: drm: Don't block the kworker waiting for mode_config.mutex in output_poll() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1fe7841d892925aff10c3b070937e974d7835d2b;p=linux-beck.git drm: Don't block the kworker waiting for mode_config.mutex in output_poll() If we cannot acquire the mode_config.mutex immediately, just back off and queue a new attempt after the poll interval. This is mostly to stop the hung task spam when the system is deadlocked, but it will also lessen the load (in such extreme cases). Signed-off-by: Chris Wilson Reviewed-by: Eric Engestrom [danvet:s/lock/mutex/ per Eric's comment.] Signed-off-by: Daniel Vetter Link: http://patchwork.freedesktop.org/patch/msgid/20161206113715.30382-1-chris@chris-wilson.co.uk --- diff --git a/drivers/gpu/drm/drm_probe_helper.c b/drivers/gpu/drm/drm_probe_helper.c index 078d9703a4fe..ac953f037be7 100644 --- a/drivers/gpu/drm/drm_probe_helper.c +++ b/drivers/gpu/drm/drm_probe_helper.c @@ -392,7 +392,11 @@ static void output_poll_execute(struct work_struct *work) if (!drm_kms_helper_poll) goto out; - mutex_lock(&dev->mode_config.mutex); + if (!mutex_trylock(&dev->mode_config.mutex)) { + repoll = true; + goto out; + } + drm_for_each_connector(connector, dev) { /* Ignore forced connectors. */