On 2022-02-17 15:08:55 [+0100], Marek Szyprowski wrote: > Hi All, Hi, > >> Marek, does this work for you? > > > > Yes, this fixed the issue. Thanks! > > > > Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> > > I've just noticed that there is one more issue left to fix (the $subject > patch is already applied) - this one comes from threaded irq (if I got > the stack trace right): netif_rx() did only set the matching softirq bit and not more. Based on that I don't see why NOHZ shouldn't complain about a pending softirq once the CPU goes idle. Therefore I think the change I made is good since it uncovered that. > ------------[ cut here ]------------ > WARNING: CPU: 0 PID: 147 at kernel/softirq.c:363 > __local_bh_enable_ip+0xa8/0x1c0 … > CPU: 0 PID: 147 Comm: irq/150-dwc3 Not tainted 5.17.0-rc4-next-20220217+ > #4557 > Hardware name: Samsung TM2E board (DT) > pstate: 400000c5 (nZcv daIF -PAN -UAO -TCO -DIT -SSBS BTYPE=--) > pc : __local_bh_enable_ip+0xa8/0x1c0 > lr : netif_rx+0xa4/0x2c0 > ... > > Call trace: > __local_bh_enable_ip+0xa8/0x1c0 > netif_rx+0xa4/0x2c0 > rx_complete+0x214/0x250 > usb_gadget_giveback_request+0x58/0x170 > dwc3_gadget_giveback+0xe4/0x200 > dwc3_gadget_endpoint_trbs_complete+0x100/0x388 > dwc3_thread_interrupt+0x46c/0xe20 So dwc3_thread_interrupt() disables interrupts here. Felipe dropped it and then added it back in e5f68b4a3e7b0 ("Revert "usb: dwc3: gadget: remove unnecessary _irqsave()"") I would suggest to revert it (the above commit) and fixing the lockdep splat in the gadget driver and other. I don't see the g_ether warning Felipe mentioned. It might come from f_ncm (since it uses a timer) or something else in the network stack (that uses a timeout timer). But not now. As much as I hate it, I suggest: diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index 183b90923f51b..a0c883f19a417 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -4160,9 +4160,11 @@ static irqreturn_t dwc3_thread_interrupt(int irq, void *_evt) unsigned long flags; irqreturn_t ret = IRQ_NONE; + local_bh_disable(); spin_lock_irqsave(&dwc->lock, flags); ret = dwc3_process_event_buf(evt); spin_unlock_irqrestore(&dwc->lock, flags); + local_bh_enable(); return ret; } In the long run I would drop that irqsave (along with bh_disable() since netif_rx() covers that) and make sure the there is no lockdep warning popping up. Marek, could you please give it a try? Sebastian