Re: [PATCH] drm/msm/atomic: Don't try async if crtc not active

[Dmitry Baryshkov]

On 18/04/2023 19:41, Rob Clark wrote:
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> For a similar reason as commit f2c7ca890182 ("drm/atomic-helper: Don't
> set deadline for modesets"), we need the crtc to be already active in
> order to compute a target vblank time for an async commit.  Otherwise
> we get this splat reminding us that we are doing it wrong:
>
>     ------------[ cut here ]------------
>     msm_dpu ae01000.mdp: drm_WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev))
>     WARNING: CPU: 7 PID: 1923 at drivers/gpu/drm/drm_vblank.c:728 drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
>     Modules linked in: snd_seq_dummy snd_seq snd_seq_device bridge stp llc tun vhost_vsock vhost vhost_iotlb vmw_vsock_virtio_transport_common vsock uinput rfcomm algif_hash algif_skcipher af_alg veth venus_dec venus_enc cros_ec_typec typec qcom_spmi_temp_alarm qcom_spmi_adc_tm5 qcom_spmi_adc5 xt_cgroup qcom_vadc_common qcom_stats hci_uart btqca xt_MASQUERADE venus_core 8021q coresight_tmc coresight_funnel coresight_etm4x coresight_replicator snd_soc_lpass_sc7180 coresight snd_soc_sc7180 ip6table_nat fuse ath10k_snoc ath10k_core ath mac80211 iio_trig_sysfs bluetooth cfg80211 cros_ec_sensors cros_ec_sensors_core ecdh_generic industrialio_triggered_buffer ecc kfifo_buf cros_ec_sensorhub r8153_ecm cdc_ether usbnet r8152 mii lzo_rle lzo_compress zram hid_vivaldi hid_google_hammer hid_vivaldi_common joydev
>     CPU: 7 PID: 1923 Comm: DrmThread Not tainted 5.15.107-18853-g3be267609a0b-dirty #16 a1ffc1a66e79c21c3536d8c9a42e819236e39714
>     Hardware name: Google Wormdingler rev1+ BOE panel board (DT)
>     pstate: 60400009 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>     pc : drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
>     lr : drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x144/0x370
>     sp : ffffffc012e2b800
>     x29: ffffffc012e2b840 x28: ffffff8083676094 x27: ffffffc012e2bb28
>     x26: ffffff8084539800 x25: 0000000000000000 x24: ffffff8083676000
>     x23: ffffffd3c8cdc5a0 x22: ffffff80845b9d00 x21: ffffffc012e2b8b4
>     x20: ffffffc012e2b910 x19: 0000000000000001 x18: 0000000000000000
>     x17: 0000000000000000 x16: 0000000000000010 x15: ffffffd3c8451a88
>     x14: 0000000000000003 x13: 0000000000000004 x12: 0000000000000001
>     x11: c0000000ffffdfff x10: ffffffd3c973ef58 x9 : 8ea3526b3cc95900
>     x8 : 8ea3526b3cc95900 x7 : 0000000000000000 x6 : 000000000000003a
>     x5 : ffffffd3c99676cd x4 : 0000000000000000 x3 : ffffffc012e2b4b8
>     x2 : ffffffc012e2b4c0 x1 : 00000000ffffdfff x0 : 0000000000000000
>     Call trace:
>      drm_crtc_vblank_helper_get_vblank_timestamp_internal+0x148/0x370
>      drm_crtc_vblank_helper_get_vblank_timestamp+0x20/0x30
>      drm_crtc_get_last_vbltimestamp+0x68/0xb0
>      drm_crtc_next_vblank_start+0x5c/0xa8
>      msm_atomic_commit_tail+0x264/0x664
>      commit_tail+0xac/0x160
>      drm_atomic_helper_commit+0x160/0x168
>      drm_atomic_commit+0xfc/0x128
>      drm_atomic_helper_disable_plane+0x8c/0x110
>      __setplane_atomic+0x10c/0x138
>      drm_mode_cursor_common+0x3a8/0x410
>      drm_mode_cursor_ioctl+0x48/0x70
>      drm_ioctl_kernel+0xe0/0x158
>      drm_ioctl+0x25c/0x4d8
>      __arm64_sys_ioctl+0x98/0xd0
>      invoke_syscall+0x4c/0x100
>      el0_svc_common+0x98/0x104
>      do_el0_svc+0x30/0x90
>      el0_svc+0x20/0x50
>      el0t_64_sync_handler+0x78/0x108
>      el0t_64_sync+0x1a4/0x1a8
>     ---[ end trace a0f587e1ab9589e8 ]---
>
> Fixes: 52ff0d3073d2 ("drm/msm/atomic: Switch to vblank_start helper")
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
> ---
>   drivers/gpu/drm/msm/msm_atomic.c | 2 ++
>   1 file changed, 2 insertions(+)

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@xxxxxxxxxx>

--
With best wishes
Dmitry