Commit bd67a8c1 authored Feb 15, 2018 by Maarten Lankhorst

drm/i915: Release connector iterator on a digital port conflict.



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 <maarten.lankhorst@linux.intel.com>
Reported-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20180215091425.42364-1-maarten.lankhorst@linux.intel.com


Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

parent d081e021

drivers/gpu/drm/i915/intel_display.c

+3 −2

Original line number	Diff line number	Diff line
		@@ -10705,6 +10705,7 @@ static bool check_digital_port_conflicts(struct drm_atomic_state *state)
		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
		@@ -10739,7 +10740,7 @@ static bool check_digital_port_conflicts(struct drm_atomic_state *state)

		/* the same port mustn't appear more than once */
		if (used_ports & port_mask)
		return false;
		ret = false;

		used_ports \|= port_mask;
		break;
		@@ -10757,7 +10758,7 @@ static bool check_digital_port_conflicts(struct drm_atomic_state *state)
		if (used_ports & used_mst_ports)
		return false;

		return true;
		return ret;
		}

		static void