From: Zeng Tao <prime.zeng@hisilicon.com>
To: <gregkh@linuxfoundation.org>, <stern@rowland.harvard.edu>,
<mathias.nyman@linux.intel.com>, <drinkcat@chromium.org>,
<felipe.balbi@linux.intel.com>, <drake@endlessm.com>,
<mike.looijmans@topic.nl>, <joe@perches.com>
Cc: Zeng Tao <prime.zeng@hisilicon.com>, <linux-usb@vger.kernel.org>,
<linux-kernel@vger.kernel.org>
Subject: [PATCH] usb: hub: try old enumeration scheme first for high speed devices
Date: Fri, 10 Aug 2018 23:01:42 +0800 [thread overview]
Message-ID: <1533913304-15737-1-git-send-email-prime.zeng@hisilicon.com> (raw)
The new scheme is required just to support legacy low and full-speed
devices. For high speed devices, it will slower the enumeration speed.
So in this patch we try the "old" enumeration scheme first for high speed
devices.
Signed-off-by: Zeng Tao <prime.zeng@hisilicon.com>
---
drivers/usb/core/hub.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1fb2668..d265b19 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2661,10 +2661,13 @@ static bool use_new_scheme(struct usb_device *udev, int retry,
int old_scheme_first_port =
port_dev->quirks & USB_PORT_QUIRK_OLD_SCHEME;
+ int quick_enumeration = (udev->speed == USB_SPEED_HIGH);
+
if (udev->speed >= USB_SPEED_SUPER)
return false;
- return USE_NEW_SCHEME(retry, old_scheme_first_port || old_scheme_first);
+ return USE_NEW_SCHEME(retry, old_scheme_first_port || old_scheme_first
+ || quick_enumeration);
}
/* Is a USB 3.0 port in the Inactive or Compliance Mode state?
--
2.7.4
next reply other threads:[~2018-08-10 7:04 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-08-10 15:01 Zeng Tao [this message]
2018-08-10 10:50 ` [PATCH] usb: hub: try old enumeration scheme first for high speed devices Roger Quadros
2018-08-10 14:19 ` Alan Stern
2018-08-14 7:35 ` Zengtao (B)
2018-08-14 14:39 ` Alan Stern
2018-08-16 6:21 ` Zengtao (B)
2018-08-16 7:16 ` Roger Quadros
2018-08-16 10:59 ` Zengtao (B)
2018-08-16 11:13 ` Roger Quadros
2018-08-17 2:15 ` Zengtao (B)
2018-08-14 7:33 ` Zengtao (B)
2018-08-16 7:31 ` Roger Quadros
2018-09-28 11:27 Zeng Tao
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