Re: [RFC] Usbcore: Do not disable USB3 protocol ports in hub_activate()

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Hello.

Greg KH wrote:

On Wed, Apr 28, 2010 at 04:04:23PM +0400, Sergei Shtylyov wrote:
Hello.

Andiry Xu wrote:

>From 7fab4880295b3af163342570d3c33ac0b51d29b5 Mon Sep 17 00:00:00 2001
From: Andiry Xu <andiry.xu@xxxxxxx>
Date: Thu, 29 Apr 2010 00:21:38 +0800
Subject: [PATCH] usbcore: Do not disable USB3 protocol ports in hub_activate

When USB3 protocol port detects an USB3.0 device attach, the port will
automatically transition to the Enabled state upon the completion
of successful link training.

Do not disable USB3 protocol ports in hub_activate(), or USB3.0 device
will fail to be recognized if xHCI bus power management is implemented.

Signed-off-by: Andiry Xu <andiry.xu@xxxxxxx>
---
 drivers/usb/core/hub.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 5c483fa..96bad49 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -745,8 +745,20 @@ static void hub_activate(struct usb_hub *hub, enum hub_activation_type type)
 				!(portstatus & USB_PORT_STAT_CONNECTION) ||
 				!udev ||
 				udev->state == USB_STATE_NOTATTACHED)) {
-			clear_port_feature(hdev, port1, USB_PORT_FEAT_ENABLE);
-			portstatus &= ~USB_PORT_STAT_ENABLE;
+			/*
+			 * USB3 protocol ports will automatically transition
+			 * to Enabled state when detect an USB3.0 device attach.
+			 * Do not disable USB3 protocol ports.
+			 * FIXME: USB3 root hub and external hubs are treated
+			 * differently here.
+			 */
+			if ((hdev->descriptor.bDeviceProtocol != 3) ||
+			    ((!hdev->parent) &&
  Parens around !x not needed.

  ... and neither around x != 3.

But it is fine to have there if they want them to.

  Parens around !x are just totally pointless.

thanks,

greg k-h

WBR, Sergei

--
To unsubscribe from this list: send the line "unsubscribe linux-usb" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux