From ba6f582606655754d9dfbfc9dffe75dcf806f1dd Mon Sep 17 00:00:00 2001 From: Sergei Antonov Date: Mon, 12 May 2014 00:30:48 +0200 Subject: [PATCH] drm/crtc-helper: skip locking checks in panicking path Skip locking checks in drm_helper_*_in_use() if they are called in panicking path. See similar code in drm_warn_on_modeset_not_all_locked(). After panic information has been output, these WARN_ONs go off outputing a lot of lines and scrolling the panic information out of the screen. Here is a partial call trace showing how execution reaches them: ? drm_helper_crtc_in_use() ? __drm_helper_disable_unused_functions() ? several *_set_config functions ? drm_fb_helper_restore_fbdev_mode() Reviewed-by: Daniel Vetter Signed-off-by: Sergei Antonov Signed-off-by: Dave Airlie --- drivers/gpu/drm/drm_crtc_helper.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_crtc_helper.c b/drivers/gpu/drm/drm_crtc_helper.c index df281b54db0..872ba11c453 100644 --- a/drivers/gpu/drm/drm_crtc_helper.c +++ b/drivers/gpu/drm/drm_crtc_helper.c @@ -29,6 +29,7 @@ * Jesse Barnes */ +#include #include #include @@ -88,7 +89,13 @@ bool drm_helper_encoder_in_use(struct drm_encoder *encoder) struct drm_connector *connector; struct drm_device *dev = encoder->dev; - WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + /* + * We can expect this mutex to be locked if we are not panicking. + * Locking is currently fubar in the panic handler. + */ + if (!oops_in_progress) + WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + list_for_each_entry(connector, &dev->mode_config.connector_list, head) if (connector->encoder == encoder) return true; @@ -112,7 +119,13 @@ bool drm_helper_crtc_in_use(struct drm_crtc *crtc) struct drm_encoder *encoder; struct drm_device *dev = crtc->dev; - WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + /* + * We can expect this mutex to be locked if we are not panicking. + * Locking is currently fubar in the panic handler. + */ + if (!oops_in_progress) + WARN_ON(!mutex_is_locked(&dev->mode_config.mutex)); + list_for_each_entry(encoder, &dev->mode_config.encoder_list, head) if (encoder->crtc == crtc && drm_helper_encoder_in_use(encoder)) return true; -- 2.41.0