Hi Kieran,
On Friday, 13 July 2018 19:01:55 EEST Kieran Bingham wrote:
> Observing this on linux-media/master branch, while running a simple
> kmstest with dual outputs (HDMI, VGA)
>
>
> Just reporting for the moment. We'll have to look at bisecting to see if
> it was introduced recently.
I haven't bisected it, but I'm pretty sure the faulty commit is
commit f81f9adc4ee1e94a38a9059f6291feea74f184e5
Author: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
Date: Thu Feb 22 14:26:21 2018 -0500
media: v4l: vsp1: Assign BRU and BRS to pipelines dynamically
I ran into the same issue today, and I'm now debugging it.
> [ 31.644076] ============================================
> [ 31.649412] WARNING: possible recursive locking detected
> [ 31.654752] 4.18.0-rc2-arm64-renesas-12862-g666e994aa227 #25 Not tainted
> [ 31.661483] --------------------------------------------
> [ 31.666818] kmstest/986 is trying to acquire lock:
> [ 31.671631] 000000008bb5ef8e (&vsp1->drm->lock){+.+.}, at:
> vsp1_du_setup_lif+0x90/0x438
> [ 31.679693]
> [ 31.679693] but task is already holding lock:
> [ 31.685551] 00000000ef2edc5c (&vsp1->drm->lock){+.+.}, at:
> vsp1_du_atomic_begin+0x1c/0x28
> [ 31.693775]
> [ 31.693775] other info that might help us debug this:
> [ 31.700331] Possible unsafe locking scenario:
> [ 31.700331]
> [ 31.706276] CPU0
> [ 31.708731] ----
> [ 31.711185] lock(&vsp1->drm->lock);
> [ 31.714864] lock(&vsp1->drm->lock);
> [ 31.718543]
> [ 31.718543] *** DEADLOCK ***
> [ 31.718543]
> [ 31.724489] May be due to missing lock nesting notation
> [ 31.724489]
> [ 31.731308] 3 locks held by kmstest/986:
> [ 31.735246] #0: 0000000073af26f9 (crtc_ww_class_acquire){+.+.}, at:
> drm_mode_atomic_ioctl+0xa0/0xa50
> [ 31.744523] #1: 000000007a933c3a (crtc_ww_class_mutex){+.+.}, at:
> drm_modeset_lock+0x64/0x118
> [ 31.753184] #2: 00000000ef2edc5c (&vsp1->drm->lock){+.+.}, at:
> vsp1_du_atomic_begin+0x1c/0x28
> [ 31.761844]
> [ 31.761844] stack backtrace:
> [ 31.766223] CPU: 1 PID: 986 Comm: kmstest Not tainted
> 4.18.0-rc2-arm64-renesas-12862-g666e994aa227 #25
> [ 31.775571] Hardware name: Renesas Salvator-X 2nd version board based
> on r8a7795 ES2.0+ (DT)
> [ 31.784047] Call trace:
> [ 31.786509] dump_backtrace+0x0/0x1c8
> [ 31.790187] show_stack+0x14/0x20
> [ 31.793521] dump_stack+0xbc/0xf4
> [ 31.796853] __lock_acquire+0x964/0x1888
> [ 31.800792] lock_acquire+0x48/0x64
> [ 31.804297] __mutex_lock+0x70/0x838
> [ 31.807887] mutex_lock_nested+0x1c/0x28
> [ 31.811826] vsp1_du_setup_lif+0x90/0x438
> [ 31.815856] rcar_du_vsp_enable+0x108/0x138
> [ 31.820057] rcar_du_crtc_setup+0x3d8/0x548
> [ 31.824258] rcar_du_crtc_atomic_begin+0x5c/0x70
> [ 31.828899] drm_atomic_helper_commit_planes+0x70/0x208
> [ 31.834147] rcar_du_atomic_commit_tail+0x30/0x68
> [ 31.838871] commit_tail+0x44/0x78
> [ 31.842287] drm_atomic_helper_commit+0xe8/0x160
> [ 31.846925] drm_atomic_commit+0x48/0x58
> [ 31.850865] drm_mode_atomic_ioctl+0x850/0xa50
> [ 31.855328] drm_ioctl_kernel+0x88/0x108
> [ 31.859267] drm_ioctl+0x1b8/0x400
> [ 31.862686] do_vfs_ioctl+0xb8/0xa20
> [ 31.866276] ksys_ioctl+0x44/0x90
> [ 31.869605] sys_ioctl+0xc/0x18
> [ 31.872759] el0_svc_naked+0x30/0x34
--
Regards,
Laurent Pinchart
