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Commit 3a22b872 authored by Lan Tianyu's avatar Lan Tianyu Committed by Greg Kroah-Hartman
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usb: Fail a get config when the port is powered off. 

Alan Stern pointed out that a USB port could potentially get powered off
when the attached USB device is in the middle of enumerating, due to
race conditions:
	http://marc.info/?l=linux-usb&m=134130616707548&w=2



If that happens, we need to ensure the enumeration fails.  If a call to
usb_get_descriptor() fails for a reason other than a Stall, return an
error.  That should handle the case where the port is powered off.

Acked-by: default avatarAlan Stern <stern@rowland.harvard.edu>
Signed-off-by: default avatarLan Tianyu <tianyu.lan@intel.com>
Signed-off-by: default avatarSarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent f7ac7787

drivers/usb/core/config.c

+2 −0
Original line number Diff line number Diff line
@@ -702,6 +702,8 @@ int usb_get_configuration(struct usb_device *dev) 
		if (result < 0) {

			dev_err(ddev, "unable to read config index %d "

			    "descriptor/%s: %d\n", cfgno, "start", result);

			if (result != -EPIPE)

				goto err;

			dev_err(ddev, "chopping to %d config(s)\n", cfgno);

			dev->descriptor.bNumConfigurations = cfgno;

			break;