Chipidea also need sync interrupt before unbind the udc while gadget remove driver, otherwise setup irq handling may happen while unbind, see below dump generated from android function switch stress test: [ 4703.503056] android_work: sent uevent USB_STATE=CONNECTED [ 4703.514642] android_work: sent uevent USB_STATE=DISCONNECTED [ 4703.651339] android_work: sent uevent USB_STATE=CONNECTED [ 4703.661806] init: Control message: Processed ctl.stop for 'adbd' from pid: 561 (system_server) [ 4703.673469] init: processing action (init.svc.adbd=stopped) from (/system/etc/init/hw/init.usb.configfs.rc:14) [ 4703.676451] Unable to handle kernel read from unreadable memory at virtual address 0000000000000090 [ 4703.676454] Mem abort info: [ 4703.676458] ESR = 0x96000004 [ 4703.676461] EC = 0x25: DABT (current EL), IL = 32 bits [ 4703.676464] SET = 0, FnV = 0 [ 4703.676466] EA = 0, S1PTW = 0 [ 4703.676468] Data abort info: [ 4703.676471] ISV = 0, ISS = 0x00000004 [ 4703.676473] CM = 0, WnR = 0 [ 4703.676478] user pgtable: 4k pages, 48-bit VAs, pgdp=000000004a867000 [ 4703.676481] [0000000000000090] pgd=0000000000000000, p4d=0000000000000000 [ 4703.676503] Internal error: Oops: 96000004 [#1] PREEMPT SMP [ 4703.758297] Modules linked in: synaptics_dsx_i2c moal(O) mlan(O) [ 4703.764327] CPU: 0 PID: 235 Comm: lmkd Tainted: G W O 5.10.9-00001-g3f5fd8487c38-dirty #63 [ 4703.773720] Hardware name: NXP i.MX8MNano EVK board (DT) [ 4703.779033] pstate: 60400085 (nZCv daIf +PAN -UAO -TCO BTYPE=--) [ 4703.785046] pc : _raw_write_unlock_bh+0xc0/0x2c8 [ 4703.789667] lr : android_setup+0x4c/0x168 [ 4703.793676] sp : ffff80001256bd80 [ 4703.796989] x29: ffff80001256bd80 x28: 00000000000000a8 [ 4703.802304] x27: ffff800012470000 x26: ffff80006d923000 [ 4703.807616] x25: ffff800012471000 x24: ffff00000b091140 [ 4703.812929] x23: ffff0000077dbd38 x22: ffff0000077da490 [ 4703.818242] x21: ffff80001256be30 x20: 0000000000000000 [ 4703.823554] x19: 0000000000000080 x18: ffff800012561048 [ 4703.828867] x17: 0000000000000000 x16: 0000000000000039 [ 4703.834180] x15: ffff8000106ad258 x14: ffff80001194c277 [ 4703.839493] x13: 0000000000003934 x12: 0000000000000000 [ 4703.844805] x11: 0000000000000000 x10: 0000000000000001 [ 4703.850117] x9 : 0000000000000000 x8 : 0000000000000090 [ 4703.855429] x7 : 6f72646e61203a70 x6 : ffff8000124f2450 [ 4703.860742] x5 : ffffffffffffffff x4 : 0000000000000009 [ 4703.866054] x3 : ffff8000108a290c x2 : ffff00007fb3a9c8 [ 4703.871367] x1 : 0000000000000000 x0 : 0000000000000090 [ 4703.876681] Call trace: [ 4703.879129] _raw_write_unlock_bh+0xc0/0x2c8 [ 4703.883397] android_setup+0x4c/0x168 [ 4703.887059] udc_irq+0x824/0xa9c [ 4703.890287] ci_irq+0x124/0x148 [ 4703.893429] __handle_irq_event_percpu+0x84/0x268 [ 4703.898131] handle_irq_event+0x64/0x14c [ 4703.902054] handle_fasteoi_irq+0x110/0x210 [ 4703.906236] __handle_domain_irq+0x8c/0xd4 [ 4703.910332] gic_handle_irq+0x6c/0x124 [ 4703.914081] el1_irq+0xdc/0x1c0 [ 4703.917221] _raw_spin_unlock_irq+0x20/0x54 [ 4703.921405] finish_task_switch+0x84/0x224 [ 4703.925502] __schedule+0x4a4/0x734 [ 4703.928990] schedule+0xa0/0xe8 [ 4703.932132] do_notify_resume+0x150/0x184 [ 4703.936140] work_pending+0xc/0x40c [ 4703.939633] Code: d5384613 521b0a69 d5184609 f9800111 (885ffd01) [ 4703.945732] ---[ end trace ba5c1875ae49d53c ]--- [ 4703.950350] Kernel panic - not syncing: Oops: Fatal exception in interrupt [ 4703.957223] SMP: stopping secondary CPUs [ 4703.961151] Kernel Offset: disabled [ 4703.964638] CPU features: 0x0240002,2000200c [ 4703.968905] Memory Limit: none [ 4703.971963] Rebooting in 5 seconds.. Fixes: 3c73bc52195d ("usb: gadget: core: sync interrupt before unbind the udc") Tested-by: faqiang.zhu <faqiang.zhu@xxxxxxx> Signed-off-by: Li Jun <jun.li@xxxxxxx> --- Change for v2 - Add fix tag to know how far this patch can be applied for stable kernels, the commit of the fix tag is not the patch introduced the problem, but the commit this patch can base on, I assume the problem exists all along. drivers/usb/chipidea/udc.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/usb/chipidea/udc.c b/drivers/usb/chipidea/udc.c index c16d900cdaee..393f216b9161 100644 --- a/drivers/usb/chipidea/udc.c +++ b/drivers/usb/chipidea/udc.c @@ -2061,6 +2061,7 @@ static int udc_start(struct ci_hdrc *ci) ci->gadget.name = ci->platdata->name; ci->gadget.otg_caps = otg_caps; ci->gadget.sg_supported = 1; + ci->gadget.irq = ci->irq; if (ci->platdata->flags & CI_HDRC_REQUIRES_ALIGNED_DMA) ci->gadget.quirk_avoids_skb_reserve = 1; -- 2.25.1