Re: [PATCH] drm/msm: Make .remove and .shutdown HW shutdown consistent

From: Javier Martinez Canillas
Date: Sun Jul 24 2022 - 05:21:46 EST

On 7/24/22 11:06, Javier Martinez Canillas wrote:

[...]

>
> I guess one option is to do the if (dev->registered) check in the callers but
> then it won't really be worth it to have a helper and we could just add that
> check in msm_drv_shutdown() to conditionally call drm_atomic_helper_shutdown().
>

By the way, the motivation of this patch is to fix a kernel oops during poweroff:

[ 169.495897] systemd-shutdown[1]: Powering off.
[ 169.500466] kvm: exiting hardware virtualization
[ 169.554787] platform wifi-firmware.0: Removing from iommu group 12
[ 169.610238] platform video-firmware.0: Removing from iommu group 10
[ 169.682164] ------------[ cut here ]------------
[ 169.686909] WARNING: CPU: 6 PID: 1 at drivers/gpu/drm/drm_modeset_lock.c:317 drm_modeset_lock_all_ctx+0x3c4/0x3d0
[ 169.697450] Modules linked in: af_alg rtl8192cu rtl_usb cros_ec_sensors rtl8192c_common cros_ec_sensors_core rtlwifi industrialio_triggered_buffer venus_enc venus_dec sbs_battery kfifo_buf cros_ec_typec videobuf2_dma_contig hid_multito
uch cros_usbpd_logger typec cros_ec_chardev cros_usbpd_charger videobuf2_memops ath10k_snoc ath10k_core hci_uart btqca venus_core btbcm ath mac80211 bluetooth v4l2_mem2mem videobuf2_v4l2 libarc4 videobuf2_common qcom_spmi_adc_tm5 qrtr cfg
80211 videodev qcom_spmi_adc5 qcom_q6v5_mss ecdh_generic qcom_pil_info ecc qcom_vadc_common mc crct10dif_ce qcom_spmi_temp_alarm rfkill qcom_q6v5 spi_geni_qcom qcom_sysmon qcom_common qmi_helpers snd_soc_max98357a socinfo ip6_tables ip_ta
bles x_tables ipmi_devintf ipmi_msghandler fuse zram zsmalloc ipv6
[ 169.767126] CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W 5.19.0-rc7+ #20
[ 169.775691] Hardware name: Google CoachZ (rev3+) (DT)
[ 169.780874] pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 169.788021] pc : drm_modeset_lock_all_ctx+0x3c4/0x3d0
[ 169.793205] lr : drm_modeset_lock_all_ctx+0x48/0x3d0
[ 169.798299] sp : ffff80000805bb80
[ 169.801701] x29: ffff80000805bb80 x28: ffff327c00128000 x27: 0000000000000000
[ 169.809025] x26: 0000000000000000 x25: 0000000000000001 x24: ffffc95d820ec030
[ 169.816349] x23: ffff327c00bbd090 x22: ffffc95d8215eca0 x21: ffff327c039c5800
[ 169.823674] x20: ffff327c039c5988 x19: ffff80000805bbe8 x18: 0000000000000034
[ 169.830998] x17: 000000040044ffff x16: ffffc95d80cac920 x15: 0000000000000000
[ 169.838322] x14: 0000000000000315 x13: 0000000000000315 x12: 0000000000000000
[ 169.845646] x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
[ 169.852971] x8 : ffff80000805bc28 x7 : 0000000000000000 x6 : 0000000000000000
[ 169.860295] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[ 169.867619] x2 : ffff327c00128000 x1 : 0000000000000000 x0 : ffff327c039c59b0
[ 169.874944] Call trace:
[ 169.877467] drm_modeset_lock_all_ctx+0x3c4/0x3d0
[ 169.882297] drm_atomic_helper_shutdown+0x70/0x134
[ 169.887217] msm_drv_shutdown+0x30/0x40
[ 169.891159] platform_shutdown+0x28/0x40
[ 169.895191] device_shutdown+0x148/0x350
[ 169.899221] kernel_power_off+0x38/0x80
[ 169.903163] __do_sys_reboot+0x288/0x2c0
[ 169.907192] __arm64_sys_reboot+0x28/0x34
[ 169.911309] invoke_syscall+0x48/0x114
[ 169.915162] el0_svc_common.constprop.0+0x44/0xec
[ 169.919992] do_el0_svc+0x2c/0xc0
[ 169.923394] el0_svc+0x2c/0x84
[ 169.926535] el0t_64_sync_handler+0x11c/0x150
[ 169.931013] el0t_64_sync+0x18c/0x190
[ 169.934777] ---[ end trace 0000000000000000 ]---
[ 169.939557] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000018
[ 169.948574] Mem abort info:
[ 169.951452] ESR = 0x0000000096000004
[ 169.955307] EC = 0x25: DABT (current EL), IL = 32 bits
[ 169.960765] SET = 0, FnV = 0
[ 169.963901] EA = 0, S1PTW = 0
[ 169.967127] FSC = 0x04: level 0 translation fault
[ 169.972136] Data abort info:
[ 169.975093] ISV = 0, ISS = 0x00000004
[ 169.979037] CM = 0, WnR = 0
[ 169.982083] user pgtable: 4k pages, 48-bit VAs, pgdp=000000010eab1000
[ 169.988697] [0000000000000018] pgd=0000000000000000, p4d=0000000000000000
[ 169.995669] Internal error: Oops: 96000004 [#1] PREEMPT SMP
[ 170.001396] Modules linked in: af_alg rtl8192cu rtl_usb cros_ec_sensors rtl8192c_common cros_ec_sensors_core rtlwifi industrialio_triggered_buffer venus_enc venus_dec sbs_battery kfifo_buf cros_ec_typec videobuf2_dma_contig hid_multito
uch cros_usbpd_logger typec cros_ec_chardev cros_usbpd_charger videobuf2_memops ath10k_snoc ath10k_core hci_uart btqca venus_core btbcm ath mac80211 bluetooth v4l2_mem2mem videobuf2_v4l2 libarc4 videobuf2_common qcom_spmi_adc_tm5 qrtr cfg
80211 videodev qcom_spmi_adc5 qcom_q6v5_mss ecdh_generic qcom_pil_info ecc qcom_vadc_common mc crct10dif_ce qcom_spmi_temp_alarm rfkill qcom_q6v5 spi_geni_qcom qcom_sysmon qcom_common qmi_helpers snd_soc_max98357a socinfo ip6_tables ip_ta
bles x_tables ipmi_devintf ipmi_msghandler fuse zram zsmalloc ipv6
[ 170.071041] CPU: 6 PID: 1 Comm: systemd-shutdow Tainted: G W 5.19.0-rc7+ #20
[ 170.079614] Hardware name: Google CoachZ (rev3+) (DT)
[ 170.084801] pstate: a0400009 (NzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
[ 170.091941] pc : ww_mutex_lock+0x28/0x32c
[ 170.096064] lr : drm_modeset_lock_all_ctx+0x1b0/0x3d0
[ 170.101254] sp : ffff80000805bb50
[ 170.104658] x29: ffff80000805bb50 x28: ffff327c00128000 x27: 0000000000000000
[ 170.111977] x26: 0000000000000000 x25: 0000000000000001 x24: 0000000000000018
[ 170.119296] x23: ffff80000805bc10 x22: ffff327c039c5ad8 x21: ffff327c039c5800
[ 170.126615] x20: ffff80000805bbe8 x19: 0000000000000018 x18: 0000000000000034
[ 170.133933] x17: 000000040044ffff x16: ffffc95d80cac920 x15: 0000000000000000
[ 170.141252] x14: 0000000000000315 x13: 0000000000000315 x12: 0000000000000000
[ 170.148571] x11: 0000000000000000 x10: 0000000000000000 x9 : 0000000000000000
[ 170.155890] x8 : ffff80000805bc28 x7 : 0000000000000000 x6 : 0000000000000000
[ 170.163209] x5 : 0000000000000000 x4 : 0000000000000000 x3 : 0000000000000000
[ 170.170528] x2 : ffff327c00128000 x1 : 0000000000000000 x0 : 0000000000000018
[ 170.177847] Call trace:
[ 170.180364] ww_mutex_lock+0x28/0x32c
[ 170.184127] drm_modeset_lock_all_ctx+0x1b0/0x3d0
[ 170.188957] drm_atomic_helper_shutdown+0x70/0x134
[ 170.193876] msm_drv_shutdown+0x30/0x40
[ 170.197820] platform_shutdown+0x28/0x40
[ 170.201854] device_shutdown+0x148/0x350
[ 170.205888] kernel_power_off+0x38/0x80
[ 170.209832] __do_sys_reboot+0x288/0x2c0
[ 170.213866] __arm64_sys_reboot+0x28/0x34
[ 170.217990] invoke_syscall+0x48/0x114
[ 170.221843] el0_svc_common.constprop.0+0x44/0xec
[ 170.226672] do_el0_svc+0x2c/0xc0
[ 170.230079] el0_svc+0x2c/0x84
[ 170.233215] el0t_64_sync_handler+0x11c/0x150
[ 170.237686] el0t_64_sync+0x18c/0x190
[ 170.241451] Code: aa0103f4 d503201f d2800001 aa0103e3 (c8e37c02)
[ 170.247704] ---[ end trace 0000000000000000 ]---
[ 170.252457] Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b
[ 170.260654] Kernel Offset: 0x495d77c00000 from 0xffff800008000000
[ 170.266910] PHYS_OFFSET: 0xffffcd8500000000
[ 170.271212] CPU features: 0x800,00c2a015,19801c82
[ 170.276042] Memory Limit: none
[ 170.279183] ---[ end Kernel panic - not syncing: Attempted to kill init! exitcode=0x0000000b ]---

--
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat