From: Chunfeng Yun Date: Sat, 10 Apr 2021 01:20:45 +0000 (+0800) Subject: usb: core: reduce power-on-good delay time of root hub X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=90d28fb53d4a;p=linux.git usb: core: reduce power-on-good delay time of root hub Return the exactly delay time given by root hub descriptor, this helps to reduce resume time etc. Due to the root hub descriptor is usually provided by the host controller driver, if there is compatibility for a root hub, we can fix it easily without affect other root hub Acked-by: Alan Stern Signed-off-by: Chunfeng Yun Link: https://lore.kernel.org/r/1618017645-12259-1-git-send-email-chunfeng.yun@mediatek.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h index 73f4482d833a7..22ea1f4f2d66d 100644 --- a/drivers/usb/core/hub.h +++ b/drivers/usb/core/hub.h @@ -148,8 +148,10 @@ static inline unsigned hub_power_on_good_delay(struct usb_hub *hub) { unsigned delay = hub->descriptor->bPwrOn2PwrGood * 2; - /* Wait at least 100 msec for power to become stable */ - return max(delay, 100U); + if (!hub->hdev->parent) /* root hub */ + return delay; + else /* Wait at least 100 msec for power to become stable */ + return max(delay, 100U); } static inline int hub_port_debounce_be_connected(struct usb_hub *hub,