Messages in this thread | | | Date | Tue, 28 Sep 2021 20:22:11 +0530 | Subject | Re: [PATCH] drm/msm: Switch ordering of runpm put vs devfreq_idle | From | Akhil P Oommen <> |
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On 9/27/2021 8:59 PM, Rob Clark wrote: > From: Rob Clark <robdclark@chromium.org> > > I've seen a few crashes like: > > Internal error: synchronous external abort: 96000010 [#1] PREEMPT SMP > Modules linked in: snd_seq_dummy snd_seq snd_seq_device bridge stp llc tun nf_nat_tftp nf_conntrack_tftp nf_nat_ftp nf_conntrack_ftp esp6 ah6 ip6t_REJECT ip6t_ipv6header vhost_vsock vhost vmw_vsock_virtio_transport_common vsock rfcomm algif_hash algif_skcipher af_alg uinput veth xt_cgroup xt_MASQUERADE venus_enc venus_dec videobuf2_dma_contig qcom_spmi_adc5 qcom_spmi_adc_tm5 hci_uart qcom_vadc_common cros_ec_typec qcom_spmi_temp_alarm typec btqca snd_soc_rt5682_i2c snd_soc_rt5682 snd_soc_sc7180 bluetooth snd_soc_qcom_common snd_soc_rl6231 ecdh_generic ecc venus_core v4l2_mem2mem snd_soc_lpass_sc7180 snd_soc_lpass_hdmi snd_soc_lpass_cpu snd_soc_lpass_platform snd_soc_max98357a ip6table_nat fuse iio_trig_sysfs cros_ec_lid_angle cros_ec_sensors cros_ec_sensors_core industrialio_triggered_buffer kfifo_buf cros_ec_sensorhub lzo_rle ath10k_snoc lzo_compress ath10k_core ath zram mac80211 cfg80211 ax88179_178a usbnet mii uvcvideo videobuf2_vmalloc joydev > CPU: 3 PID: 212 Comm: A618-worker Tainted: G W 5.4.139-16300-g88d8e1285982 #1 > Hardware name: Google Pompom (rev1) with LTE (DT) > pstate: 60c00009 (nZCv daif +PAN +UAO) > pc : a6xx_gmu_set_oob+0x114/0x200 > lr : a6xx_gmu_set_oob+0x10c/0x200 > sp : ffffffc011b7bc20 > x29: ffffffc011b7bc20 x28: ffffffdad27c5000 > x27: 0000000000000001 x26: ffffffdad1521044 > x25: ffffffbef7498338 x24: 0000000000000018 > x23: 0000000000000002 x22: 0000000000014648 > x21: 0000033732fe638b x20: 0000000080000000 > x19: ffffffbef7433bc8 x18: 0000000040000000 > x17: 000000243508d982 x16: 000000000000b67e > x15: 00000000000090d4 x14: 0000000000000024 > x13: 0000000000000024 x12: 0000000000017521 > x11: 0000000000000b48 x10: 0000000000326a48 > x9 : 1a130d33f6371600 x8 : ffffffc011e54648 > x7 : 614948e00005003c x6 : ffffffbe3cd17e60 > x5 : 0000000000000040 x4 : 0000000000000004 > x3 : 0000000000000000 x2 : ffffffbef7488000 > x1 : ffffffbef7488000 x0 : 0000000000000000 > Call trace: > a6xx_gmu_set_oob+0x114/0x200 > a6xx_gmu_set_freq+0xe0/0x1fc > msm_devfreq_target+0x80/0x13c > msm_devfreq_idle+0x54/0x94 > retire_submit+0x170/0x254 > retire_submits+0xa4/0xdc > retire_worker+0x1c/0x28 > kthread_worker_fn+0xf4/0x1bc > kthread+0x140/0x158 > ret_from_fork+0x10/0x18 > Code: 52800c81 9415bbe5 f9400a68 8b160108 (b9400108) > ---[ end trace 16b871df2482cd61 ]--- > Kernel panic - not syncing: Fatal exception > SMP: stopping secondary CPUs > Kernel Offset: 0x1ac1400000 from 0xffffffc010000000 > PHYS_OFFSET: 0xffffffc280000000 > CPU features: 0x88102e,2a80aa38 > Memory Limit: none > > Which smells a lot like touching hw after power collapse. I'm not > *entirely* sure how it could have taken 66ms (the autosuspend delay) > before we get to a6xx_gmu_set_oob(), but to be safe we should move > the pm_runtime_put_autosuspend() after msm_devfreq_idle(). https://elixir.bootlin.com/linux/v5.15-rc1/source/drivers/gpu/drm/msm/adreno/a6xx_gmu.c#L132 We have this check in the gmu freq set path which should avoid this scenario. I might be a bit pedantic here, but I feel that the original code is more accurate. We should immediately mark last busy and put runtime_pm refcount.
-Akhil.
> > Fixes: 9bc95570175a ("drm/msm: Devfreq tuning") > Signed-off-by: Rob Clark <robdclark@chromium.org> > --- > drivers/gpu/drm/msm/msm_gpu.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/msm/msm_gpu.c b/drivers/gpu/drm/msm/msm_gpu.c > index d1a16642ecd5..2b2bbe7499e6 100644 > --- a/drivers/gpu/drm/msm/msm_gpu.c > +++ b/drivers/gpu/drm/msm/msm_gpu.c > @@ -667,9 +667,6 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring, > > msm_submit_retire(submit); > > - pm_runtime_mark_last_busy(&gpu->pdev->dev); > - pm_runtime_put_autosuspend(&gpu->pdev->dev); > - > spin_lock_irqsave(&ring->submit_lock, flags); > list_del(&submit->node); > spin_unlock_irqrestore(&ring->submit_lock, flags); > @@ -683,6 +680,9 @@ static void retire_submit(struct msm_gpu *gpu, struct msm_ringbuffer *ring, > mutex_unlock(&gpu->active_lock); > > msm_gem_submit_put(submit); > + > + pm_runtime_mark_last_busy(&gpu->pdev->dev); > + pm_runtime_put_autosuspend(&gpu->pdev->dev); > } > > static void retire_submits(struct msm_gpu *gpu) >
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