> > Wouldn't handle_nested_irq() work here instead of the simple thingy? > > Daniel could you try this suggestion? Would it work? [ 6.427289] ------------[ cut here ]------------ [ 6.431977] kernel BUG at drivers/net/phy/mdio_bus.c:626! [ 6.437453] Internal error: Oops - BUG: 0 [#1] PREEMPT SMP [ 6.443013] Modules linked in: [ 6.446116] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.4.0-rc3-00100-g70cc5ab156c3-dirty #50 [ 6.454763] Hardware name: Raspberry Pi 3 Model B+ (DT) [ 6.460062] pstate: 00000005 (nzcv daif -PAN -UAO) [ 6.464928] pc : mdiobus_read+0x68/0x70 [ 6.468821] lr : lan88xx_phy_ack_interrupt+0x1c/0x30 [ 6.473852] sp : ffff800010003d70 [ 6.477208] x29: ffff800010003d70 x28: 0000000000000000 [ 6.482597] x27: 0000000000000001 x26: 0000000000000060 [ 6.487985] x25: 00000000000000e0 x24: ffff8000113ca680 [ 6.493373] x23: ffff0000372ac174 x22: ffff00003768f6d4 [ 6.498762] x21: ffff00003768f600 x20: 0000000000000000 [ 6.504149] x19: ffff0000372c1000 x18: 000000000000000e [ 6.509537] x17: 0000000000000001 x16: 0000000000000007 [ 6.514923] x15: 000000000000000e x14: 0000000000000013 [ 6.520311] x13: 0000000000000000 x12: 0000000000000000 [ 6.525699] x11: 000000000000057b x10: 0000000000000003 [ 6.531087] x9 : ffff0000383f4750 x8 : ffff0000383f3dc0 [ 6.536474] x7 : ffff0000374be100 x6 : ffff0000383f4750 [ 6.541862] x5 : ffff000037cab700 x4 : 0000000000000008 [ 6.547249] x3 : 0000000000000101 x2 : 000000000000001a [ 6.552636] x1 : 0000000000000001 x0 : ffff0000372c0800 [ 6.558023] Call trace: [ 6.560506] mdiobus_read+0x68/0x70 [ 6.564045] phy_interrupt+0x5c/0xb0 [ 6.567672] handle_nested_irq+0xb8/0x130 [ 6.571740] intr_complete+0xb0/0xe0 [ 6.575368] __usb_hcd_giveback_urb+0x58/0xf8 [ 6.579787] usb_giveback_urb_bh+0xac/0x108 [ 6.584032] tasklet_action_common.isra.0+0x154/0x1a0 [ 6.589155] tasklet_hi_action+0x24/0x30 [ 6.593134] __do_softirq+0x120/0x23c [ 6.596847] irq_exit+0xb8/0xd8 [ 6.600031] __handle_domain_irq+0x64/0xb8 [ 6.604183] bcm2836_arm_irqchip_handle_irq+0x60/0xc0 [ 6.609305] el1_irq+0xb8/0x180 [ 6.612490] arch_cpu_idle+0x10/0x18 [ 6.616115] do_idle+0x200/0x280 [ 6.619387] cpu_startup_entry+0x20/0x40 [ 6.623366] rest_init+0xd4/0xe0 [ 6.626642] arch_call_rest_init+0xc/0x14 [ 6.630706] start_kernel+0x420/0x44c [ 6.634425] Code: a94153f3 a9425bf5 a8c37bfd d65f03c0 (d4210000) [ 6.640614] ---[ end trace 97efd7bf12ed0c65 ]--- [ 6.645295] Kernel panic - not syncing: Fatal exception in interrupt [ 6.651740] SMP: stopping secondary CPUs [ 6.655719] Kernel Offset: disabled [ 6.659254] CPU features: 0x0002,24002004 [ 6.663315] Memory Limit: none [ 6.666416] ---[ end Kernel panic - not syncing: Fatal exception in interrupt ]--- Not really. It turns out phy_interrupt() wants to be run in a threaded context. As Sebastian says on IRC "but this means, that it was broken from the beginning"
