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UPSTREAM: usb: core: reduce power-on-good delay time of root hub

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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

(cherry picked from commit 90d28fb53d)
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/1618017645-12259-1-git-send-email-chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Change-Id: I53b813a1f32b2657b000146de27759bb736e0e51
This commit is contained in:
Chunfeng Yun 2021-04-10 09:20:45 +08:00 • committed by Greg Kroah-Hartman
commit 4d5d751670
1 changed files with 4 additions and 2 deletions
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6
drivers/usb/core/hub.h
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@ -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,