From: Maarten Lankhorst Date: Thu, 15 Feb 2018 10:14:25 +0100 Subject: drm/i915: Release connector iterator on a digital port conflict. Git-commit: bd67a8c15a3b59ea9b21aee31e867c728661977d Patch-mainline: v4.17-rc1 References: FATE#326289 FATE#326079 FATE#326049 FATE#322398 FATE#326166 Hitting the failure path through check_digital_port_conflicts triggers: ================================================ WARNING: lock held when returning to user space! 4.16.0-rc1-CI-kasan_1+ #1 Tainted: G W ------------------------------------------------ kms_3d/1439 is leaving the kernel with locks still held! 1 lock held by kms_3d/1439: #0: (drm_connector_list_iter){.+.+}, at: [<000000003745d183>] intel_atomic_check+0x1d9d/0x3ff0 [i915] Rearrange the code to have a single exit path through the unlock. Signed-off-by: Maarten Lankhorst Reported-by: Chris Wilson Link: https://patchwork.freedesktop.org/patch/msgid/20180215091425.42364-1-maarten.lankhorst@linux.intel.com Reviewed-by: Chris Wilson Reviewed-by: Rodrigo Vivi Acked-by: Petr Tesarik --- drivers/gpu/drm/i915/intel_display.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -10721,6 +10721,7 @@ static bool check_digital_port_conflicts struct drm_connector_list_iter conn_iter; unsigned int used_ports = 0; unsigned int used_mst_ports = 0; + bool ret = true; /* * Walk the connector list instead of the encoder @@ -10755,7 +10756,7 @@ static bool check_digital_port_conflicts /* the same port mustn't appear more than once */ if (used_ports & port_mask) - return false; + ret = false; used_ports |= port_mask; break; @@ -10773,7 +10774,7 @@ static bool check_digital_port_conflicts if (used_ports & used_mst_ports) return false; - return true; + return ret; } static void