Endpoint Mode: Raising legacy interrupt causes BUG: Scheduling while Atomic
Mar 04, 2024
Endpoint: Xavier AGX on custom carrier 5.0.2/35.1
Root: generic x86 pc on linux 5.10
I’m working on a kernel module to use the endpoint functionality. I’m trying to raise a legacy interrupt on the endpoint but it runs into a BUG: scheduling while atomic.
I don’t believe I am entering atomic context within any of my code. This is a very basic “hello world” level module. I also don’t use any spinlocks/mutexes within my code. At least not directly. I know the EPC has a mutex on any ops. Not sure if that matters. Is there another source of entering atomic context that is not obvious?
I know I can modify tegra_pcie_ep_raise_irq and replace usleep_range with udelay. But I’m trying to avoid something like that.
pci_epc_raise_irq(epc, epf->func_no, PCI_EPC_IRQ_LEGACY, 0);
[ 278.572774] BUG: scheduling while atomic: kworker/0:2H/597/0x00000003
[ 278.573045] Modules linked in: ac_epf_test(OE) fuse lzo_rle lzo_compress zram aes_ce_ccm realtek snd_soc_tegra186_asrc iwlmvm snd_soc_tegra186_dspk snd_soc_tegra210_ope snd_soc_tegra186_arad snd_soc_tegra210_iqc mac80211 snd_soc_tegra210_mvc snd_soc_tegra210_admaif snd_soc_tegra210_afc snd_soc_tegra210_dmic snd_soc_tegra210_amx snd_soc_tegra210_adx snd_soc_tegra_pcm snd_soc_tegra210_mixer snd_soc_tegra210_i2s snd_soc_tegra210_sfc aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce sha2_ce sha256_arm64 sha1_ce snd_soc_spdif_tx snd_soc_tegra_machine_driver binfmt_misc max77620_thermal nct1008 snd_soc_rt5659 snd_soc_tegra210_adsp snd_soc_rl6231 snd_soc_tegra_utils snd_soc_simple_card_utils bluedroid_pm snd_soc_tegra210_ahub iwlwifi tegra_bpmp_thermal nvadsp userspace_alert tegra210_adma snd_hda_codec_hdmi cfg80211 snd_hda_tegra spi_tegra114 snd_hda_codec snd_hda_core loop ina3221 pwm_fan nvgpu nvmap ramoops reed_solomon ip_tables x_tables
[ 278.574315] CPU: 0 PID: 597 Comm: kworker/0:2H Tainted: G OE 5.10.104-tegra #1
[ 278.574323] Hardware name: Unknown Jetson-AGX/Jetson-AGX, BIOS 1.0-d7fb19b 08/10/2022
[ 278.574387] Workqueue: kactest ac_epf_test_cmd_handler [ac_epf_test]
[ 278.574402] Call trace:
[ 278.574453] dump_backtrace+0x0/0x1d0
[ 278.574465] show_stack+0x30/0x40
[ 278.574490] dump_stack+0xd8/0x138
[ 278.574510] __schedule_bug+0x78/0x90
[ 278.574530] __schedule+0x844/0x910
[ 278.574538] schedule+0x78/0x110
[ 278.574553] schedule_hrtimeout_range_clock+0xa0/0x120
[ 278.574562] schedule_hrtimeout_range+0x3c/0x50
[ 278.574570] usleep_range+0x6c/0xa0
[ 278.574600] tegra_pcie_ep_raise_irq+0x84/0x100
[ 278.574609] dw_pcie_ep_raise_irq+0x4c/0x70
[ 278.574621] pci_epc_raise_irq+0x84/0xd0
[ 278.574631] ac_epf_test_cmd_handler+0x110/0x13c [ac_epf_test]
[ 278.574654] process_one_work+0x1c4/0x4a0
[ 278.574662] worker_thread+0x54/0x430
[ 278.574692] kthread+0x148/0x170
[ 278.574702] ret_from_fork+0x10/0x24
[ 278.574813] BUG: workqueue leaked lock or atomic: kworker/0:2H/0xfffffffe/597
last function: ac_epf_test_cmd_handler [ac_epf_test]
[ 278.575182] CPU: 0 PID: 597 Comm: kworker/0:2H Tainted: G W OE 5.10.104-tegra #1
[ 278.575195] Hardware name: Unknown Jetson-AGX/Jetson-AGX, BIOS 1.0-d7fb19b 08/10/2022
[ 278.575213] Workqueue: kactest ac_epf_test_cmd_handler [ac_epf_test]
[ 278.575230] Call trace:
[ 278.575242] dump_backtrace+0x0/0x1d0
[ 278.575252] show_stack+0x30/0x40
[ 278.575300] dump_stack+0xd8/0x138
[ 278.575309] process_one_work+0x498/0x4a0
[ 278.575317] worker_thread+0x54/0x430
[ 278.575324] kthread+0x148/0x170
[ 278.575332] ret_from_fork+0x10/0x24
[ 278.575346] BUG: scheduling while atomic: kworker/0:2H/597/0xffffffff
[ 278.575507] Modules linked in: ac_epf_test(OE) fuse lzo_rle lzo_compress zram aes_ce_ccm realtek snd_soc_tegra186_asrc iwlmvm snd_soc_tegra186_dspk snd_soc_tegra210_ope snd_soc_tegra186_arad snd_soc_tegra210_iqc mac80211 snd_soc_tegra210_mvc snd_soc_tegra210_admaif snd_soc_tegra210_afc snd_soc_tegra210_dmic snd_soc_tegra210_amx snd_soc_tegra210_adx snd_soc_tegra_pcm snd_soc_tegra210_mixer snd_soc_tegra210_i2s snd_soc_tegra210_sfc aes_ce_blk crypto_simd cryptd aes_ce_cipher ghash_ce sha2_ce sha256_arm64 sha1_ce snd_soc_spdif_tx snd_soc_tegra_machine_driver binfmt_misc max77620_thermal nct1008 snd_soc_rt5659 snd_soc_tegra210_adsp snd_soc_rl6231 snd_soc_tegra_utils snd_soc_simple_card_utils bluedroid_pm snd_soc_tegra210_ahub iwlwifi tegra_bpmp_thermal nvadsp userspace_alert tegra210_adma snd_hda_codec_hdmi cfg80211 snd_hda_tegra spi_tegra114 snd_hda_codec snd_hda_core loop ina3221 pwm_fan nvgpu nvmap ramoops reed_solomon ip_tables x_tables
[ 278.575934] CPU: 0 PID: 597 Comm: kworker/0:2H Tainted: G W OE 5.10.104-tegra #1
[ 278.575940] Hardware name: Unknown Jetson-AGX/Jetson-AGX, BIOS 1.0-d7fb19b 08/10/2022
[ 278.576087] Workqueue: 0x0 (kactest)
[ 278.576103] Call trace:
[ 278.576115] dump_backtrace+0x0/0x1d0
[ 278.576125] show_stack+0x30/0x40
[ 278.576132] dump_stack+0xd8/0x138
[ 278.576140] __schedule_bug+0x78/0x90
[ 278.576149] __schedule+0x844/0x910
[ 278.576156] schedule+0x78/0x110
[ 278.576164] worker_thread+0xc0/0x430
[ 278.576171] kthread+0x148/0x170
[ 278.576178] ret_from_fork+0x10/0x24