Commit 0a723ed3 authored by Marcello Sylvester Bauer's avatar Marcello Sylvester Bauer Committed by Greg Kroah-Hartman
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usb: gadget: dummy_hcd: Set transfer interval to 1 microframe 



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: default avatarMarcello Sylvester Bauer <marcello.bauer@9elements.com>
Signed-off-by: default avatarMarcello Sylvester Bauer <sylv@sylv.io>
Link: https://lore.kernel.org/r/6295dbb84ca76884551df9eb157cce569377a22c.1712843963.git.sylv@sylv.io


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent a7f3813e

drivers/usb/gadget/udc/dummy_hcd.c

+4 −2
Original line number Diff line number Diff line
@@ -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);