Patchwork [3.5.y.z,extended,stable] Patch "USB: Prepare for refactoring by adding extra udev checks." has been added to staging queue

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Submitter Luis Henriques
Date March 13, 2013, 8:06 p.m.
Message ID <1363205183-9006-1-git-send-email-luis.henriques@canonical.com>
Download mbox | patch
Permalink /patch/227346/
State New
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Comments

Luis Henriques - March 13, 2013, 8:06 p.m.
This is a note to let you know that I have just added a patch titled

    USB: Prepare for refactoring by adding extra udev checks.

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

From 4f31727adcc17b9fffaf28dd702deba9df314f7d Mon Sep 17 00:00:00 2001
From: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Date: Thu, 7 Mar 2013 16:24:22 -0800
Subject: [PATCH] USB: Prepare for refactoring by adding extra udev checks.

commit 2d4fa940f99663c82ba55b2244638833b388e4e2 upstream.

[This is upstream commit 2d4fa940f99663c82ba55b2244638833b388e4e2.
It needs to be backported to kernels as old as 3.2, because it fixes the
buggy commit 9dbcaec830cd97f44a0b91b315844e0d7144746b "USB: Handle warm
reset failure on empty port."]

The next patch will refactor the hub port code to rip out the recursive
call to hub_port_reset on a failed hot reset.  In preparation for that,
make sure all code paths can deal with being called with a NULL udev.
The usb_device will not be valid if warm reset was issued because a port
transitioned to the Inactive or Compliance Mode on a device connect.

This patch should have no effect on current behavior.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
---
 drivers/usb/core/hub.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

--
1.8.1.2

Patch

diff --git a/drivers/usb/core/hub.c b/drivers/usb/core/hub.c
index 1a2cd0e..15b6be0 100644
--- a/drivers/usb/core/hub.c
+++ b/drivers/usb/core/hub.c
@@ -2475,6 +2475,9 @@  static int hub_port_wait_reset(struct usb_hub *hub, int port1,
 				return -ENOTCONN;

 			if ((portstatus & USB_PORT_STAT_ENABLE)) {
+				if (!udev)
+					return 0;
+
 				if (hub_is_wusb(hub))
 					udev->speed = USB_SPEED_WIRELESS;
 				else if (hub_is_superspeed(hub->hdev))
@@ -2518,13 +2521,15 @@  static void hub_port_finish_reset(struct usb_hub *hub, int port1,
 			struct usb_hcd *hcd;
 			/* TRSTRCY = 10 ms; plus some extra */
 			msleep(10 + 40);
-			update_devnum(udev, 0);
-			hcd = bus_to_hcd(udev->bus);
-			/* The xHC may think the device is already reset,
-			 * so ignore the status.
-			 */
-			if (hcd->driver->reset_device)
-				hcd->driver->reset_device(hcd, udev);
+			if (udev) {
+				update_devnum(udev, 0);
+				hcd = bus_to_hcd(udev->bus);
+				/* The xHC may think the device is already
+				 * reset, so ignore the status.
+				 */
+				if (hcd->driver->reset_device)
+					hcd->driver->reset_device(hcd, udev);
+			}
 		}
 		/* FALL THROUGH */
 	case -ENOTCONN:
@@ -2538,7 +2543,7 @@  static void hub_port_finish_reset(struct usb_hub *hub, int port1,
 			clear_port_feature(hub->hdev, port1,
 					USB_PORT_FEAT_C_PORT_LINK_STATE);
 		}
-		if (!warm)
+		if (!warm && udev)
 			usb_set_device_state(udev, *status
 					? USB_STATE_NOTATTACHED
 					: USB_STATE_DEFAULT);