From: Marcello Sylvester Bauer <sylv@xxxxxxx> commit 0a723ed3baa941ca4f51d87bab00661f41142835 upstream. Currently, the transfer polling interval is set to 1ms, which is the frame rate of full-speed and low-speed USB. The USB 2.0 specification introduces microframes (125 microseconds) to improve the timing precision of data transfers. Reducing the transfer interval to 1 microframe increases data throughput for high-speed and super-speed USB communication Signed-off-by: Marcello Sylvester Bauer <marcello.bauer@xxxxxxxxxxxxx> Signed-off-by: Marcello Sylvester Bauer <sylv@xxxxxxx> Link: https://lore.kernel.org/r/6295dbb84ca76884551df9eb157cce569377a22c.1712843963.git.sylv@xxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Guilherme G. Piccoli <gpiccoli@xxxxxxxxxx> --- drivers/usb/gadget/udc/dummy_hcd.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c index dab559d8ee8c..f37b0d8386c1 100644 --- a/drivers/usb/gadget/udc/dummy_hcd.c +++ b/drivers/usb/gadget/udc/dummy_hcd.c @@ -50,6 +50,8 @@ #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 */ + static const char driver_name[] = "dummy_hcd"; static const char driver_desc[] = "USB Host+Gadget Emulator"; @@ -1302,7 +1304,7 @@ static int dummy_urb_enqueue( /* kick the scheduler, it'll do the rest */ if (!hrtimer_active(&dum_hcd->timer)) - hrtimer_start(&dum_hcd->timer, ms_to_ktime(1), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL); done: spin_unlock_irqrestore(&dum_hcd->dum->lock, flags); @@ -1993,7 +1995,7 @@ static enum hrtimer_restart dummy_timer(struct hrtimer *t) dum_hcd->udev = NULL; } else if (dum_hcd->rh_state == DUMMY_RH_RUNNING) { /* want a 1 msec delay here */ - hrtimer_start(&dum_hcd->timer, ms_to_ktime(1), HRTIMER_MODE_REL); + hrtimer_start(&dum_hcd->timer, ns_to_ktime(DUMMY_TIMER_INT_NSECS), HRTIMER_MODE_REL); } spin_unlock_irqrestore(&dum->lock, flags); -- 2.46.2
