[PATCH] drm/scheduler: fix drm_sched_job_add_implicit_dependencies

[Yassine Oudjana]

On Tue, 2021-10-19 at 13:27 +0200, Christian König wrote:
> Trivial fix since we now need to grab a reference to the fence we have
> added. Previously the dma_resv function where doing that for us.
> 
> Signed-off-by: Christian König <christian.koenig at amd.com>
> Fixes: 9c2ba265352a drm/scheduler: ("use new iterator in drm_sched_job_add_implicit_dependencies v2")
> ---
>  drivers/gpu/drm/scheduler/sched_main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
> index 5bc5f775abe1..94fe51b3caa2 100644
> --- a/drivers/gpu/drm/scheduler/sched_main.c
> +++ b/drivers/gpu/drm/scheduler/sched_main.c
> @@ -707,6 +707,9 @@ int drm_sched_job_add_implicit_dependencies(struct drm_sched_job *job,
>  		ret = drm_sched_job_add_dependency(job, fence);
>  		if (ret)
>  			return ret;
> +
> +		/* Make sure to grab an additional ref on the added fence */
> +		dma_fence_get(fence);
>  	}
>  	return 0;
>  }

Fixes this error on Qualcomm MSM8996:

[   16.493786] Unable to handle kernel paging request at virtual address 0000100000000000
[   16.493823] Mem abort info:
[   16.493832]   ESR = 0x96000004
[   16.493843]   EC = 0x25: DABT (current EL), IL = 32 bits
[   16.493855]   SET = 0, FnV = 0
[   16.493864]   EA = 0, S1PTW = 0
[   16.493874]   FSC = 0x04: level 0 translation fault
[   16.493884] Data abort info:
[   16.493893]   ISV = 0, ISS = 0x00000004
[   16.493902]   CM = 0, WnR = 0
[   16.493912] user pgtable: 4k pages, 48-bit VAs, pgdp=000000011e406000
[   16.493924] [0000100000000000] pgd=0000000000000000, p4d=0000000000000000
[   16.493949] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[   16.493961] Modules linked in: q6asm_dai q6routing q6afe_dai q6asm q6adm snd_q6dsp_common
snd_soc_wcd9335 venus_enc venus_dec panel_lgphilips_sw43101 videobuf2_dma_contig q6afe
regmap_slimbus videobuf2_memops q6core apr ath10k_pci ath10k_core ath mac80211 libarc4 venus_core
cfg80211 v4l2_mem2mem videobuf2_v4l2 videobuf2_common videodev mc msm hci_uart nxp_nci_i2c nxp_nci
slim_qcom_ngd_ctrl btqca pdr_interface gpu_sched slimbus drm_kms_helper nci syscopyarea sysfillrect
bluetooth sysimgblt fb_sys_fops nfc qcom_spmi_haptics rfkill qcom_q6v5_pas qcom_q6v5_mss
qcom_pil_info qcom_common qcom_q6v5 qcom_sysmon qmi_helpers snd_soc_apq8096 mdt_loader
snd_soc_qcom_common snd_soc_core snd_compress snd_pcm snd_timer snd soundcore lzo_rle socinfo
rpmsg_char pwm_ir_tx rmtfs_mem zram atmel_mxt_ts drm drm_panel_orientation_quirks ip_tables
[   16.494320] CPU: 1 PID: 521 Comm: phoc:sq0 Not tainted 5.16.0-rc1+ #68
[   16.494335] Hardware name: Xiaomi Mi Note 2 (DT)
[   16.494346] pstate: 60000005 (nZCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[   16.494362] pc : drm_sched_job_add_dependency+0xe0/0x214 [gpu_sched]
[   16.494396] lr : drm_sched_job_add_dependency+0x70/0x214 [gpu_sched]
[   16.494417] sp : ffff800013e2baf0
[   16.494427] x29: ffff800013e2baf0 x28: 0000000000000002 x27: 000000000000001b
[   16.494452] x26: ffff000099ad0200 x25: 000000000000001a x24: 0000000000000010
[   16.494476] x23: ffff000098e99800 x22: 0000000000000000 x21: 0000000000000000
[   16.494500] x20: ffff000098e99870 x19: ffff000081e50940 x18: 0000000000000000
[   16.494524] x17: 0000000000000000 x16: 0000000000000000 x15: 0000ffff83a4576c
[   16.494548] x14: 0000000000000000 x13: 0000000000000000 x12: 0000000000000040
[   16.494571] x11: ffff00009f19fb50 x10: ffff00009f19fb52 x9 : 0000000000000001
[   16.494595] x8 : 0000000000000228 x7 : ffffffffffffffff x6 : 0000000000000001
[   16.494619] x5 : ffff800013e2bab8 x4 : ffff800013e2bab8 x3 : 0000100000000000
[   16.494643] x2 : 0000100000000000 x1 : fffffc0002f04640 x0 : ffff000081e50940
[   16.494668] Call trace:
[   16.494679]  drm_sched_job_add_dependency+0xe0/0x214 [gpu_sched]
[   16.494702]  drm_sched_job_add_implicit_dependencies+0x60/0x9c [gpu_sched]
[   16.494724]  msm_ioctl_gem_submit+0xe98/0x179c [msm]
[   16.494871]  drm_ioctl_kernel+0xc4/0x16c [drm]
[   16.495046]  drm_ioctl+0x214/0x44c [drm]
[   16.495162]  __arm64_sys_ioctl+0xa8/0xf0
[   16.495183]  invoke_syscall+0x48/0x114
[   16.495201]  el0_svc_common.constprop.0+0x44/0xfc
[   16.495215]  do_el0_svc+0x28/0x90
[   16.495229]  el0_svc+0x28/0x80
[   16.495243]  el0t_64_sync_handler+0xa4/0x130
[   16.495255]  el0t_64_sync+0x1a0/0x1a4
[   16.495275] Code: d50323bf d65f03c0 f9400662 f9401403 (39400042) 
[   16.495291] ---[ end trace cbfcea8f309d97a1 ]---

Tested-by: Yassine Oudjana <y.oudjana at protonmail.com>