diff options
| author | Marcello Sylvester Bauer <sylv@sylv.io> | 2024-04-11 17:22:11 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-04-18 16:47:07 +0200 |
| commit | 0a723ed3baa941ca4f51d87bab00661f41142835 (patch) | |
| tree | c63bdd4268b8911f665d91ee85648f094d138bfd | |
| parent | a7f3813e589fd8e2834720829a47b5eb914a9afe (diff) | |
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: Marcello Sylvester Bauer <marcello.bauer@9elements.com>
Signed-off-by: Marcello Sylvester Bauer <sylv@sylv.io>
Link: https://lore.kernel.org/r/6295dbb84ca76884551df9eb157cce569377a22c.1712843963.git.sylv@sylv.io
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | drivers/usb/gadget/udc/dummy_hcd.c | 6 |
1 files 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 @@ return_urb: 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); |