From: Marcello Sylvester Bauer <sylv@xxxxxxx>
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>
---
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);
--
2.44.0
