drm/rockchip: Fix crash when find connector from bridge

The function drm_connector_list_iter_end() will be called
twice when connector is found, that will cause crash.

crash:

[    1.201561] Unable to handle kernel read from unreadable memory at virtual address 0000000000000318
[    2.886426] Mem abort info:
[    2.889222]   ESR = 0x96000005
[    2.892276]   Exception class = DABT (current EL), IL = 32 bits
[    2.898189]   SET = 0, FnV = 0
[    2.901244]   EA = 0, S1PTW = 0
[    2.904379] Data abort info:
[    2.907256]   ISV = 0, ISS = 0x00000005
[    2.911086]   CM = 0, WnR = 0
[    2.914058] [0000000000000318] user address but active_mm is swapper
[    2.920410] Internal error: Oops: 96000005 [#1] PREEMPT SMP
[    2.925983] Modules linked in:
[    2.929041] Process kworker/5:1 (pid: 60, stack limit = 0x00000000e4da41d3)
[    2.935997] CPU: 5 PID: 60 Comm: kworker/5:1 Not tainted 4.19.111 rockchip-linux#200
[    2.942522] Hardware name: Rockchip RK3368 R88 AVB (DT)
[    2.947753] Workqueue: events deferred_probe_work_func
[    2.952895] pstate: 60400085 (nZCv daIf +PAN -UAO)
[    2.957686] pc : __ll_sc___cmpxchg_case_acq_4+0x4/0x20
[    2.962828] lr : _raw_spin_lock_irqsave+0x34/0x70
[    2.967529] sp : ffffff8009cc38e0
[    2.970843] x29: ffffff8009cc38e0 x28: ffffffc03dedb8b8
[    2.976158] x27: ffffffc03ded4480 x26: ffffff8009cc3a28
[    2.981465] x25: ffffffc03decbdd8 x24: ffffffc03dedcd90
[    2.986780] x23: ffffff80096ed000 x22: ffffffc00a2dd890
[    2.992095] x21: ffffff80091fbe20 x20: 0000000000000318
[    2.997410] x19: 0000000000000000 x18: ffffffffffffffff
[    3.002726] x17: 0000000000000000 x16: 0000000000000000
[    3.008042] x15: ffffff80096eda48 x14: ffffff80898b7e37
[    3.013357] x13: ffffff80098b7e45 x12: ffffff80098b8280
[    3.018673] x11: ffffff800970e000 x10: 0000000005f5e0ff
[    3.023989] x9 : 00000000ffffffd0 x8 : 625f79625f726f74
[    3.029296] x7 : 0000000000000030 x6 : 000000000000024a
[    3.034602] x5 : 0000000000000000 x4 : 0000000000000000
[    3.039907] x3 : 0000000000000318 x2 : 0000000000000001
[    3.045222] x1 : 0000000000000000 x0 : 0000000000000318
[    4.266041] Call trace:
[    4.268489]  __ll_sc___cmpxchg_case_acq_4+0x4/0x20
[    4.273279]  drm_connector_list_iter_end+0x2c/0x58
[    4.278068]  rockchip_drm_bind+0x1c20/0x1c38
[    4.282338]  try_to_bring_up_master+0x144/0x1a8
[    4.286867]  component_master_add_with_match+0xd4/0x130
[    4.292090]  rockchip_drm_platform_probe+0x178/0x2e8
[    4.297054]  platform_drv_probe+0x50/0xa8
[    4.301065]  really_probe+0x200/0x2b0
[    4.304734]  driver_probe_device+0x58/0x100
[    4.308921]  __device_attach_driver+0x90/0xc0
[    4.313274]  bus_for_each_drv+0x70/0xc8
[    4.317110]  __device_attach+0xdc/0x138
[    4.320944]  device_initial_probe+0x10/0x18
[    4.325131]  bus_probe_device+0x94/0xa0
[    4.328965]  deferred_probe_work_func+0x80/0xb8
[    4.333497]  process_one_work+0x1a0/0x418
[    4.337508]  worker_thread+0x1e4/0x3e0
[    4.341260]  kthread+0x12c/0x158
[    4.344493]  ret_from_fork+0x10/0x18
[    4.348072]  Code: 35ffff91 aa1003e0 d65f03c0 f980001 (885ffc10)

Change-Id: I0a3c9e038b4ffe31feaa8356a0ce3e62f6f3c374
Signed-off-by: Algea Cao <[email protected]>

rk-5.4-drm 56fe1c4

drivers/gpu/drm/rockchip/rockchip_drm_drv.c

@@ -179,7 +179,6 @@ struct drm_connector *find_connector_by_bridge(struct drm_device *drm_dev,
 	drm_connector_list_iter_begin(drm_dev, &conn_iter);
 	drm_for_each_connector_iter(connector, &conn_iter) {
 		if (connector->port == np_connector) {
-			drm_connector_list_iter_end(&conn_iter);
 			found_connector = true;
 			break;
 		}