diff options
| author | Hemant Kumar <hemantk@codeaurora.org> | 2016-11-08 15:25:25 -0800 |
|---|---|---|
| committer | Hemant Kumar <hemantk@codeaurora.org> | 2016-11-10 11:14:27 -0800 |
| commit | 49ba0d0ad43d530f141ab3995cdd7d7c5e00230d (patch) | |
| tree | ceae68e9ff7758f55d15aa53ff85d1698aa06497 | |
| parent | 286fd3fcbf748c2a7fa204bcb4618e6fe60c3ea1 (diff) | |
usb: core: Add support to skip extended bus resume delay
By default skip_extended_resume_delay module parameter
allows to skip extra 40ms delay upon usb bus resume.
This delay was added on top of host bus resume which
is driven for 20ms. Skipping extra delay reduces over
all bus resume latency.
Change-Id: I31a83abc057c345f29d204a63e7571b880678e69
Signed-off-by: Hemant Kumar <hemantk@codeaurora.org>
| -rw-r--r-- | drivers/usb/core/hub.c | 10 |
1 files changed, 8 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c index 515d34c091e1..5839111ab4e0 100644 --- a/drivers/usb/core/hub.c +++ b/drivers/usb/core/hub.c @@ -48,6 +48,11 @@ static void hub_event(struct work_struct *work); /* synchronize hub-port add/remove and peering operations */ DEFINE_MUTEX(usb_port_peer_mutex); +static bool skip_extended_resume_delay = 1; +module_param(skip_extended_resume_delay, bool, S_IRUGO | S_IWUSR); +MODULE_PARM_DESC(skip_extended_resume_delay, + "removes extra delay added to finish bus resume"); + /* cycle leds on hubs that aren't blinking for attention */ static bool blinkenlights = 0; module_param(blinkenlights, bool, S_IRUGO); @@ -3434,8 +3439,9 @@ int usb_port_resume(struct usb_device *udev, pm_message_t msg) /* drive resume for USB_RESUME_TIMEOUT msec */ dev_dbg(&udev->dev, "usb %sresume\n", (PMSG_IS_AUTO(msg) ? "auto-" : "")); - usleep_range(USB_RESUME_TIMEOUT * 1000, - (USB_RESUME_TIMEOUT + 1) * 1000); + if (!skip_extended_resume_delay) + usleep_range(USB_RESUME_TIMEOUT * 1000, + (USB_RESUME_TIMEOUT + 1) * 1000); /* Virtual root hubs can trigger on GET_PORT_STATUS to * stop resume signaling. Then finish the resume |