On Sun, Oct 13, 2024 at 11:38:03AM -0700, syzbot wrote: > Hello, > > syzbot has tested the proposed patch and the reproducer did not trigger any issue: Evidently there's still too much debugging output. Reduce it even more. Alan Stern #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing Index: usb-devel/drivers/usb/gadget/udc/dummy_hcd.c =================================================================== --- usb-devel.orig/drivers/usb/gadget/udc/dummy_hcd.c +++ usb-devel/drivers/usb/gadget/udc/dummy_hcd.c @@ -50,7 +50,7 @@ #define POWER_BUDGET 500 /* in mA; use 8 for low-power port testing */ #define POWER_BUDGET_3 900 /* in mA */ -#define DUMMY_TIMER_INT_NSECS 125000 /* 1 microframe */ +#define DUMMY_INT_KTIME ns_to_ktime(125000) /* 1 microframe */ static const char driver_name[] = "dummy_hcd"; static const char driver_desc[] = "USB Host+Gadget Emulator"; @@ -257,6 +257,8 @@ struct dummy_hcd { unsigned active:1; unsigned old_active:1; unsigned resuming:1; + + bool alanflag; }; struct dummy { @@ -1304,7 +1306,7 @@ static int dummy_urb_enqueue( /* kick the scheduler, it'll do the rest */ if (!hrtimer_active(&dum_hcd->timer)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), + hrtimer_start(&dum_hcd->timer, DUMMY_INT_KTIME, HRTIMER_MODE_REL_SOFT); done: @@ -1325,9 +1327,15 @@ static int dummy_urb_dequeue(struct usb_ rc = usb_hcd_check_unlink_urb(hcd, urb, status); if (!rc && dum_hcd->rh_state != DUMMY_RH_RUNNING && - !list_empty(&dum_hcd->urbp_list)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL_SOFT); - + !list_empty(&dum_hcd->urbp_list)) { + dev_info(dummy_dev(dum_hcd), "Dequeue restart %p\n", urb); + hrtimer_start(&dum_hcd->timer, DUMMY_INT_KTIME, + HRTIMER_MODE_REL_SOFT); + } else { + dev_info(dummy_dev(dum_hcd), "Dequeue norestart: %d %p\n", + rc, urb); + } + dum_hcd->alanflag = true; spin_unlock_irqrestore(&dum_hcd->dum->lock, flags); return rc; } @@ -1813,6 +1821,8 @@ static enum hrtimer_restart dummy_timer( /* look at each urb queued by the host side driver */ spin_lock_irqsave(&dum->lock, flags); + if (dum_hcd->alanflag) + dev_info(dummy_dev(dum_hcd), "Timer handler\n"); if (!dum_hcd->udev) { dev_err(dummy_dev(dum_hcd), @@ -1984,6 +1994,8 @@ return_urb: ep->already_seen = ep->setup_stage = 0; usb_hcd_unlink_urb_from_ep(dummy_hcd_to_hcd(dum_hcd), urb); + if (dum_hcd->alanflag) + dev_info(dummy_dev(dum_hcd), "Giveback %p\n", urb); spin_unlock(&dum->lock); usb_hcd_giveback_urb(dummy_hcd_to_hcd(dum_hcd), urb, status); spin_lock(&dum->lock); @@ -1995,11 +2007,11 @@ return_urb: usb_put_dev(dum_hcd->udev); dum_hcd->udev = NULL; } else if (dum_hcd->rh_state == DUMMY_RH_RUNNING) { - /* want a 1 msec delay here */ - hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), + hrtimer_start(&dum_hcd->timer, DUMMY_INT_KTIME, HRTIMER_MODE_REL_SOFT); } + dum_hcd->alanflag = false; spin_unlock_irqrestore(&dum->lock, flags); return HRTIMER_NORESTART; @@ -2391,7 +2403,8 @@ static int dummy_bus_resume(struct usb_h dum_hcd->rh_state = DUMMY_RH_RUNNING; set_link_state(dum_hcd); if (!list_empty(&dum_hcd->urbp_list)) - hrtimer_start(&dum_hcd->timer, ns_to_ktime(0), HRTIMER_MODE_REL_SOFT); + hrtimer_start(&dum_hcd->timer, DUMMY_INT_KTIME, + HRTIMER_MODE_REL_SOFT); hcd->state = HC_STATE_RUNNING; } spin_unlock_irq(&dum_hcd->dum->lock);
