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authorChunfeng Yun <chunfeng.yun@mediatek.com>2021-04-10 09:20:45 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2021-06-03 08:38:12 +0200
commit4e400034553096aaf9efb7cea398cffa9f695a12 (patch)
treee917a7ab7a8ea70f560a8dc2286daabeb5e46e72
parent210946e53a372e8fba194d142e8a74c880ceff5b (diff)
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usb: core: reduce power-on-good delay time of root hub
commit 90d28fb53d4a51299ff324dede015d5cb11b88a2 upstream. 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 <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>
-rw-r--r--drivers/usb/core/hub.h6
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/usb/core/hub.h b/drivers/usb/core/hub.h
index d0bbbd76ba8e..df3aa0b69188 100644
--- a/drivers/usb/core/hub.h
+++ b/drivers/usb/core/hub.h
@@ -146,8 +146,10 @@ 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,