Pali Rohár <pali@xxxxxxxxxx> [2020-10-07 10:12:27]: Hi, [adding Koen to Cc:] > I'm hitting these race conditions randomly on pci aardvark controller > driver- I prepared patch which speed up initialization of this driver, > but also increase probability that it hits above race conditions :-( it seems, that I'm able to reproduce this race condition on every boot with 5.10 on my Freescale i.MX6Q board, see the log excerpt bellow. I don't know if this helps, but it's not happening on 5.4 kernel. [ 0.000000] Booting Linux on physical CPU 0x0 [ 0.000000] Linux version 5.10.27 (ynezz@ntbk) (arm-openwrt-linux-muslgnueabi-gcc (OpenWrt GCC 8.4.0 r12719+30-84f4a783c698) 8.4.0, GNU ld (GNU Binutils) 2.34) #0 SMP Wed Apr 7 12:52:23 2021 [ 0.000000] CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c5387d [ 0.000000] CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache [ 0.000000] OF: fdt: Machine model: Toradex Apalis iMX6Q/D Module on Ixora Carrier Board ... [ 2.239498] pci 0000:00:00.0: BAR 0: assigned [mem 0x01000000-0x010fffff] [ 2.266430] pci 0000:00:00.0: BAR 6: assigned [mem 0x01100000-0x0110ffff pref] ����#���+$HH��.274570] pci 0000:00:00.0: Max Payload Size set to 128/ 128 (was 128), Max Read Rq 128 (this serial console hiccup during PCI initialization seems quite strange as well, happens always) [ 2.283074] sysfs: cannot create duplicate filename '/devices/platform/soc/1ffc000.pcie/pci0000:00/0000:00:00.0/config' [ 2.293884] CPU: 1 PID: 47 Comm: kworker/u8:3 Not tainted 5.10.27 #0 [ 2.300165] random: fast init done [ 2.300249] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree) [ 2.310186] Workqueue: events_unbound async_run_entry_fn [ 2.315507] Backtrace: [ 2.317976] [<8010cc88>] (dump_backtrace) from [<8010d134>] (show_stack+0x20/0x24) [ 2.325556] r7:813283d4 r6:60000013 r5:00000000 r4:80ec845c [ 2.331236] [<8010d114>] (show_stack) from [<805971fc>] (dump_stack+0xa4/0xb8) [ 2.338480] [<80597158>] (dump_stack) from [<803a7128>] (sysfs_warn_dup+0x68/0x74) [ 2.346058] r7:813283d4 r6:80af0dfc r5:812f48f0 r4:81afa000 [ 2.351726] [<803a70c0>] (sysfs_warn_dup) from [<803a6c90>] (sysfs_add_file_mode_ns+0x100/0x1cc) [ 2.360518] r7:813283d4 r6:812f48f0 r5:80b4299c r4:ffffffef [ 2.366187] [<803a6b90>] (sysfs_add_file_mode_ns) from [<803a6fe8>] (sysfs_create_bin_file+0x94/0x9c) [ 2.375411] r6:81eb8078 r5:80b4299c r4:00000000 [ 2.380043] [<803a6f54>] (sysfs_create_bin_file) from [<805da848>] (pci_create_sysfs_dev_files+0x58/0x2cc) [ 2.389701] r6:81eb8000 r5:81eb8078 r4:81eb8000 [ 2.394341] [<805da7f0>] (pci_create_sysfs_dev_files) from [<805cba98>] (pci_bus_add_device+0x34/0x90) [ 2.403659] r10:80b45d88 r9:81818810 r8:81328200 r7:813283d4 r6:8190c000 r5:81eb8078 [ 2.411490] r4:81eb8000 [ 2.414034] [<805cba64>] (pci_bus_add_device) from [<805cbb30>] (pci_bus_add_devices+0x3c/0x80) [ 2.421744] random: crng init done [ 2.422737] r5:8190c014 r4:81eb8000 [ 2.429720] [<805cbaf4>] (pci_bus_add_devices) from [<805cf898>] (pci_host_probe+0x50/0xa0) [ 2.438078] r7:813283d4 r6:8190c000 r5:8190c00c r4:00000000 [ 2.443753] [<805cf848>] (pci_host_probe) from [<805eeb20>] (dw_pcie_host_init+0x1d0/0x414) [ 2.452111] r7:813283d4 r6:81328058 r5:00000200 r4:00000000 [ 2.457780] [<805ee950>] (dw_pcie_host_init) from [<805ef5a8>] (imx6_pcie_probe+0x38c/0x69c) [ 2.466226] r10:81226180 r9:ef0205c4 r8:81818800 r7:81328040 r6:81328040 r5:81818810 [ 2.474060] r4:00000020 [ 2.476615] [<805ef21c>] (imx6_pcie_probe) from [<8065e858>] (platform_drv_probe+0x58/0xa8) [ 2.484977] r10:80ec9f78 r9:00000000 r8:80f160a8 r7:00000000 r6:80ec9f78 r5:00000000 [ 2.492809] r4:81818810 [ 2.495357] [<8065e800>] (platform_drv_probe) from [<8065c0a0>] (really_probe+0x128/0x534) [ 2.503627] r7:00000000 r6:80f5b8c4 r5:81818810 r4:80f5b8d4 [ 2.509296] [<8065bf78>] (really_probe) from [<8065c700>] (driver_probe_device+0x88/0x200) [ 2.517570] r10:00000000 r9:80f0bb60 r8:00000000 r7:80f160a8 r6:80ec9f78 r5:80ec9f78 [ 2.525401] r4:81818810 [ 2.527946] [<8065c678>] (driver_probe_device) from [<8065c904>] (__driver_attach_async_helper+0x8c/0xb4) [ 2.537521] r9:80f0bb60 r8:00000000 r7:8104d000 r6:80ec9f78 r5:80f25010 r4:81818810 [ 2.545273] [<8065c878>] (__driver_attach_async_helper) from [<8015b930>] (async_run_entry_fn+0x58/0x1bc) [ 2.554843] r6:819fb480 r5:80f25010 r4:819fb490 [ 2.559479] [<8015b8d8>] (async_run_entry_fn) from [<8015114c>] (process_one_work+0x238/0x5ac) [ 2.568099] r8:00000000 r7:8104d000 r6:81048400 r5:8127a080 r4:819fb490 [ 2.574811] [<80150f14>] (process_one_work) from [<8015152c>] (worker_thread+0x6c/0x5c0) [ 2.582909] r10:81048400 r9:80e03d00 r8:81048418 r7:00000088 r6:81048400 r5:8127a094 [ 2.590742] r4:8127a080 [ 2.593290] [<801514c0>] (worker_thread) from [<80158168>] (kthread+0x174/0x178) [ 2.600694] r10:8127a080 r9:812e3024 r8:8116fe74 r7:813c0000 r6:00000000 r5:8127b040 [ 2.608527] r4:812e3000 [ 2.611073] [<80157ff4>] (kthread) from [<80100148>] (ret_from_fork+0x14/0x2c) [ 2.618302] Exception stack(0x813c1fb0 to 0x813c1ff8) [ 2.623362] 1fa0: 00000000 00000000 00000000 00000000 [ 2.631548] 1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [ 2.639731] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [ 2.646354] r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80157ff4 [ 2.654187] r4:8127b040 [ 2.657157] pcieport 0000:00:00.0: PME: Signaling with IRQ 316 [ 2.674770] VFS: Mounted root (squashfs filesystem) readonly on device 179:2. [ 2.686264] Freeing unused kernel memory: 1024K Complete serial console log http://sprunge.us/wCe6zs Cheers, Petr
