On stable rc 5.8.15 the following kernel warning was noticed once while boot and this is hard to reproduce.
metadata: git branch: linux-5.8.y git repo: https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc git commit: f4ed6fb8f1680de812daf362f28342e6bf19fdcc git describe: v5.8.14-125-gf4ed6fb8f168 make_kernelversion: 5.8.15-rc1 kernel-config: https://builds.tuxbuild.com/5nFtomB9FDlQVjafKdyR9A/kernel.config
warning log: ---------------- [ 43.512935] ------------[ cut here ]------------ [ 43.517563] WARNING: CPU: 0 PID: 424 at kernel/irq/chip.c:242 __irq_startup+0xa8/0xb0 [ 43.517564] Modules linked in: caam error crct10dif_ce ina2xx lm90 qoriq_thermal fuse [ 43.533218] CPU: 0 PID: 424 Comm: (agetty) Not tainted 5.8.15-rc1 #1 [ 43.533219] Hardware name: Freescale Layerscape 2088A RDB Board (DT) [ 43.533223] pstate: 60000085 (nZCv daIf -PAN -UAO BTYPE=--) [ 43.533225] pc : __irq_startup+0xa8/0xb0 [ 43.533229] lr : irq_startup+0x64/0x140 [ 43.559218] sp : ffff800010b838c0 [ 43.559219] x29: ffff800010b838c0 x28: ffff0082cd3bab00 [ 43.559222] x27: ffffb8c772ed8ec0 x26: 0000000000020902 [ 43.573133] x25: ffffb8c771d39e68 x24: ffffb8c771d39b08 [ 43.573135] x23: 0000000000000000 x22: 0000000000000001 [ 43.573138] x21: 0000000000000001 x20: ffff0082edf42c40 [ 43.573140] x19: ffff0082ede29200 x18: 0000000000000001 [ 43.573142] x17: 0000000000000000 x16: 0000000000000000 [ 43.573145] x15: ffff0082edf430c0 x14: ffff800010bf5000 [ 43.573147] x13: ffff800010bed000 x12: ffff800010be9000 [ 43.573149] x11: 0000000000000040 x10: ffffb8c772cdb940 [ 43.573153] x9 : ffffb8c770b7fe0c x8 : ffff0082ee000270 [ 43.620866] x7 : 0000000000000000 x6 : ffffb8c772cbaa08 [ 43.620869] x5 : ffffb8c772cba000 x4 : 0000000000000504 [ 43.620871] x3 : ffff0082ede29200 x2 : 0000000003032004 [ 43.636780] x1 : 0000000003032004 x0 : ffff0082ede29258 [ 43.636783] Call trace: [ 43.636786] __irq_startup+0xa8/0xb0 [ 43.636789] irq_startup+0x64/0x140 [ 43.651569] __enable_irq+0x78/0x88 [ 43.651571] enable_irq+0x54/0xa8 [ 43.651577] serial8250_do_startup+0x670/0x718 [ 43.662791] serial8250_startup+0x30/0x40 [ 43.666793] uart_startup.part.0+0x12c/0x2e0 [ 43.671055] uart_port_activate+0x68/0xa0 [ 43.675058] tty_port_open+0x98/0x250 [ 43.678712] uart_open+0x24/0x38 [ 43.681932] tty_open+0x100/0x480 [ 43.685240] chrdev_open+0xac/0x1a8 [ 43.688721] do_dentry_open+0x130/0x3d0 [ 43.692548] vfs_open+0x34/0x40 [ 43.695681] path_openat+0x888/0xde8 [ 43.699247] do_filp_open+0x80/0x108 [ 43.702814] do_sys_openat2+0x1ec/0x2a8 [ 43.706642] do_sys_open+0x60/0xa8 [ 43.710035] __arm64_sys_openat+0x2c/0x38 [ 43.714037] el0_svc_common.constprop.0+0x7c/0x198 [ 43.718820] do_el0_svc+0x2c/0x98 [ 43.722128] el0_sync_handler+0x9c/0x1b8 [ 43.726041] el0_sync+0x158/0x180 [ 43.729347] ---[ end trace 434ed7c8787a1d1f ]---
full log, https://qa-reports.linaro.org/lkft/linux-stable-rc-linux-5.8.y/build/v5.8.14...